Title of Invention	METHOD FOR THE ESTABLISHMENT OF A CONNECTION IN RADIO COMMUNICATION SYSTEM
Abstract	The invention relates to a method for establishment of a connection in a radio communication system, wherein a user terminal (UE) selects an operator (OPI), based on information (info) on at least one operator (OPI,OP2) of a radio communication system in a country-specific pilot channel (C-CPC), selects a radio communication system (RATI,IMTS) based on information (info) on at least one radio communication system in an operator-secific pilot channel (OPI-CPC) for the selected operator (OPI) and carries out an access to the selected radio communication system (RATI,UMTS) for establishment of a connection.

Title of Invention

METHOD FOR THE ESTABLISHMENT OF A CONNECTION IN RADIO COMMUNICATION SYSTEM

Abstract

The invention relates to a method for establishment of a connection in a radio communication system, wherein a user terminal (UE) selects an operator (OPI), based on information (info) on at least one operator (OPI,OP2) of a radio communication system in a country-specific pilot channel (C-CPC), selects a radio communication system (RATI,IMTS) based on information (info) on at least one radio communication system in an operator-secific pilot channel (OPI-CPC) for the selected operator (OPI) and carries out an access to the selected radio communication system (RATI,UMTS) for establishment of a connection.

Full Text	Description ESTABLISHMENT OF A CONNECTION IN RADIO COMMUNICATION SYSTEMS The invention relates to a method for the establishment of a connection in radio communication systems, particularly in mobile radio systems, and to components of the radio communication system for carrying out the method according to the invention. A continuously rising number of different radio communication systems, to mention only the systems according to the familiar GSM, IS-95, UMTS, CDMA2000, WLAN, WiMAX, etc. standards, for example, leads to user terminals also supporting an ever increasing number of these systems or standards and, as a result, providing the user with access to communication networks in the most varied manner. In addition, operators of radio communication systems are increasingly providing their customers with systems of different standards, with the possibility of roaming between these systems. However, all this can disadvantageously lead to the period for establishing a connection by a user terminal being extended due to the large selection of available systems which, in addition, operate in different system-specific frequency bands, as a rule. If, for example, the user wishes to use a high-data-rate service, to mention video streaming as an example, such a service can be potentially provided by different systems. If no specific system has been preselected by the user, the user terminal, during the establishment of the connection, establishes contact to various systems or, respectively, the user terminal first attempts to receive signals from different systems - for example of the same operator - and then to select a system suitable for the selected service. Especially when the user terminal is taken into operation at a location which it has previously not maintained a connection to a system and can thus not make use of empirical values, for example if the user is located in a foreign country after a flight, an additional aggravating factor which may extend the access time is that the local operator is not known, with whom the home operator has concluded a so-called roaming agreement in order to provide lowered connection charges to the customer. In this case, a local system or operator may be proposed to the user a number of times, with which the user must then decide whether a connection establishment is to take place or not. From DE 197 34 933 C1, a method is known in which a mobile station located in a radio coverage area of a mobile radio network generates an adaptation to an air interface access method of the mobile radio network by signaling information transmitted on a pilot channel. In this context, the pilot channel is transmitted by at least one broadcast transmitting station of a public broadcasting system in the radio coverage area of the mobile radio network and received and evaluated by the mobile station. To provide an overview of the increasing number of systems for users or user terminals, it has already been proposed, inter alia in the document "Global Pilot Mechanism" Tdoc SMG2 UMTS 52/97, ETSI STC SMG2 UMTS adhoc, April 8-10, 1997, Lulea, Sweden, pages 1 and 2, to introduce a globally uniform pilot channel (Global Pilot Channel) on a uniform frequency channel or in a uniform frequency spectrum. On such a global pilot channel, information about the respective locally available radio access technologies (Radio Access Technology Indicator) and references (Spectral Pointers) to their spectral position should be transmitted so that a user terminal can select and access a suitable or supported radio access technology. Radio access technologies are understood to be systems of different standards, for example GSM and UMTS which operate in different frequency bands. According to the above document, the pilot channel should be sent out either by the operators themselves which would correspondingly also have to send out information by competing operators, or by a national entity not specified in greater detail, for example the regulating authority. However, such a uniform pilot channel has the disadvantage that with the rising number of different systems and their expansion to a greater number of frequency bands, the signaling load would also rise continuously. In addition, the administrative effort for acquiring and sending out information of the different systems appears to be comparatively large. Furthermore, a user terminal, after having been referred to the frequency spectrum, for example of the GSM mobile radio system, by means of the pilot channel, would still have to perform a large number of measurements of networks of different operators in order to find an operator network which is suitable for the desired service or the desired tariff or contract. It is the object of the invention, therefore, to specify a method, a system and system components which enable a user terminal to establish a connection setup to a desired radio communication system or network in a simple and quick manner. This object is achieved by the features of the independent patent claims. Advantageous embodiments of the invention can be found in dependent patent claims. According to the invention, a user terminal selects an operator on the basis of information on at least one operator of a radio communication system in a country-specific pilot channel. Following this, the user terminal selects a radio communication system on the basis of information on at least one radio communication system in an operator-specific pilot channel of the selected operator and, finally, carries out an access to the selected radio communication system for the establishment of a connection. Advantageously, the hierarchical structure of the pilot channels according to the invention and a corresponding subdivision of the information in each case transmitted in the pilot channels provides for a simpler and more flexible administration of the contents of the pilot channels compared with the method of the prior art, described by way of the introduction. Thus, for example, a change of the systems or networks supported by an operator does not require any change in the content of the country-specific pilot channel which, if necessary, is administered by a higher- level entity, for example a national regulating authority. Advantageously, the respective operator can also dynamically change, for example the assignment of physical resources to the individual systems or networks in the sense of a dynamic resource assignment in the pilot channel allocated to him, for example in order to optimize a load distribution in the systems or networks. In this context, the content of the operator- specific pilot channel is advantageously configured, for example, by the operator himself, for example by means of a correspondingly designed operation and maintenance function (O&M). If a number of operators use the same frequency spectrum, the current use and its corresponding signaling should preferably take place in agreement with one another on the operator-specific pilot channels. In the same manner, the user terminal is advantageously enabled to pass through a uniform connection setup procedure in order to carry out a quick establishment of a connection to a desired system or network independently of its current location. According to a further development of the invention, a reference to at least the operator-specific pilot channel is transmitted as information in the country-specific pilot channel. By means of this information, the user terminal can directly access the operator-specific pilot channel. The same applies to another development according to which a reference to at least one system-specific pilot channel of the at least one radio communication system is transmitted as information in the operator-specific pilot channel. In accordance with a further embodiment of the method according to the invention, information of a synchronization channel, control channel and/or pilot channel is transmitted in the system-specific pilot channel. In this context, the information is dependent on the respective configuration of the radio interface or the radio transmission standard, respectively, and can have a different content in dependence on the system or standard. According to a further embodiment, the at least one operator- specific pilot channel and the at least one system-specific pilot channel are sent out by at least one radio access device of the at least one radio communication system. This has the advantageous effect that the number of devices involved in the sending out of the pilot channels is limited. According to a further development, the country-specific pilot channel is also sent out by at least one radio access device of the at least one radio communication system and/or a broadcast transmitting station of a public or private broadcasting system. Using broadcast transmitting stations offers the advantage that, by using facilities which are already in existence, large geographic areas can be covered with one radio cell. In this context, long transit times which may be due to the size of the radio cell do not have a negative effect since the signal transmission is exclusively in the downward direction, i.e. in the direction of the user terminals. According to a further development of the invention, information on operators, with whom the at least one operator maintains national and/or international roaming agreements, is additionally transmitted in the country-specific pilot channel. This enables a user terminal which is located outside its own network to obtain in a simple manner an overview of the locally available operators and finally to select one operator. According to a further development, the information on operators with roaming agreements can be transmitted in specific frames within a sequence of frames of the country-specific pilot channel. According to a further embodiment of the invention, finally, a reconfigurability of the user terminal by means of a transmission of information with respect to a system-specific configuration of the user terminal in the operator-specific pilot channel is supported, as a result of which the user terminal can be advantageously adapted to the radio access method of the selected system even before an access to the system. The system according to the invention and system components in each case have devices according to the invention by means of which the method according to the invention can be realized. In the text which follows, the invention will be presented in greater detail by means of an exemplary embodiment, in which: figure 1 shows a representation of coverage areas of respective pilot channels, figure 2 shows a representation of the hierarchical structure of the pilot channels and their contents, figure 3 shows a flowchart of an access of a user terminal to a system, figure 4 shows a sequence of frames of a country-specific pilot channel, figures 5a, 5b show structures of frames with information with respect to operators with roaming agreements, figure 6 shows the structure of an operator-specific frame with a subfield for reconfigurable terminals, and figure 7 shows a representation of system components. Figure 1 shows by way of example the respective coverage areas of the pilot channels according to the invention. It shall be assumed in this context that a country-specific pilot channel C-CPC (Country level Common Pilot Channel) radiates information channel C-CPC by means of broadcast transmitting stations, it can also be sent out by the systems of the operators themselves. Apart from the first operator 0P1 operating nationwide, figure 1 also shows by way of example the coverage area of a second, locally operating operator 0P2 with three radio cells of a wireless access system according to the so-called WiMAX standard (IEEE 802.16). Furthermore, a user terminal UE which is located in the coverage area of systems and networks both of the first operator OP1 and of the second operator OP2, and is thus potentially capable of establishing a connection to each of these systems, is shown by way of example. For subsequent explanations it shall be assumed that the user terminal UE is technically constructed to support the three standards mentioned by way of example, wherein the method can be similarly carried out for user terminals which only support one of the standards. In the exemplary situation of figure 1, it shall also be assumed that the user terminal UE is switched on or taken into operation for the first time. This occurs, for example, after the purchase of the terminal by the user or after arrival at the airport after a trip from another country. To establish a first contact to a system operating at the location of the user terminal, the user terminal will first tune itself to the frequency band of the country-specific pilot channel C-CPC, receive it and evaluate information contained therein and then select a suitable or predetermined operator, for example on the basis of operator information or roaming agreements of operators stored in the SIM card. As mentioned before, the frequency band and the access technology of the country- specific pilot channel C-CPC is preferably known per se to the user terminal UE so that the country-specific pilot channel C-CPC can be selectively and rapidly accessed. On the basis of the information contained in the country- specific pilot channel C-CPC, the user terminal UE thus selects a suitable or predetermined operator and subsequently tunes the receiving device to the operator-specific pilot channel of the selected operator by means of a reference contained in the information of the country-specific pilot channel C-CPC. A cellular structure, described above, of the country-specific pilot channel advantageously enables regional or local peculiarities to be taken into consideration and, as a result, to limit the volume of information to be transmitted in the pilot channel. Thus, for example, in the case where an operator operates in a locally limited way and thus exclusively in one particular one of the multiplicity of cells of the country- specific pilot channel, information and a reference to this operator could be sent out exclusively in this cell whereas no information whatsoever relating to this operator is sent out in all other cells of the country-specific pilot channel in which this operator is not operating. This would correspondingly apply if an operator, for example, operates wireless access networks exclusively in metropolitan areas. In this case, it would be sufficient that only the cells of the country-specific pilot channel which comprise the metropolitan areas affected send out information and references to this operator. In the operator-specific pilot channel, in turn, information with respect to the systems and networks supported by the operator is transmitted so that the user terminal UE can subsequently select and access a suitable system or network, respectively. The user terminal UE is preferably again referred to the selected system or network by means of a reference to a system-specific pilot channel, synchronization channel or control channel contained in the information of the operator- specific pilot channel. In the text which follows, the term pilot channel will be used as synonym for such system-specific channels. In this context, the operator- specific pilot channel is transmitted, corresponding to the country-specific pilot channel, preferably in a uniform frequency band, for example in a subfrequency band of the country-specific pilot channel in order to provide for rapid access by the user terminal wherein, as an alternative, a limited number of frequency bands also appears to be possible and appropriate, in turn. Figure 2 shows by way of example the hierarchical structure according to the invention of the pilot channels and a respective exemplary frame structure, referring to the situation of figure 1. The country-specific pilot channel C-CPC is composed, for example, of the several subfields of different content, shown in figure 2, wherein these subfields can also be transmitted in a different order in the sense of the invention. Together, the subfields produce a frame which is sent out periodically as mentioned above, for example by broadcast transmitting stations or operator stations. The beginning of a frame is identified by a start field or starting sequence Start. This Start field can contain information about the identity of the pilot channel, for example with regard to the fact that this is a country-specific pilot channel, in contrast to an operator-specific pilot channel, but also a synchronization sequence which enables a user terminal to synchronize itself to the transmission in the pilot channel, and for detecting the beginning of a respective frame. In a second subfield, following the start field start, of the country-specific pilot channel C-CPC, a country code (CC) is preferably transmitted on the basis of which the receiving user terminal UE can identify the country in the territorial field of which it is currently located. This country code CC can be used by the user terminal, for example, for matching it with information, stored on the SIM card or an integrated memory, relating to operators of this country, for example with respect to existing roaming agreements. Following the second subfield of the country code CC, information info with respect to the operators OP1, OP2, ..., OPn operating in the coverage area of the country-specific pilot channel C-CPC, including a respective reference to the operator-specific pilot channel or channels OP1-CPC, OP2-CPC, ..., OPn-CPC (Operator level Common Pilot Channel) is transmitted in respective subfields. This information enables the user terminal UE, after evaluation and the abovementioned matching, to select a suitable operator, the first operator 0P1 in the example of figure 2, and to directly access the pilot channel or channels OP1-CPC of this selected first operator OP1 by means of the reference. Finally, a frame of the country-specific pilot channel C-CPC is preferably concluded by a subfield with an end sequence End. In the case of a periodic repetition of the transmission of the frame and unambiguous identifiability of the beginning of a frame by means of the start field, however, a transmission of the subfield of the end sequence End can also be omitted, however. At the hierarchy level of the operator, a corresponding frame structure of a pilot channel is used but with at least partially different content of the subfields. The operator- specific pilot channel is also preferably periodically repeatedly sent out. Figure 2 shows by way of example the frame structure of the operator-specific pilot channel OPl-CPC of the first operator 0P1 selected by the user terminal UE. Since, as a rule, the operator-specific pilot channel OP1-CPC is sent out in a frequency band disjoint from the country- specific pilot channel C-CPC, an identification of the beginning of a respective frame by means of a start field Start is again appropriate. Corresponding to the described field of the country-specific pilot channel C-CPC, this Start field can again contain information about the identity of the pilot channel, for example with regard to the fact that this is an operator-specific pilot channel, in contrast to the country- specific pilot channel C-CPC, but also a synchronization sequence which enables a user terminal to synchronize itself to the transmissions in the pilot channel. A frame of the operator-specific pilot channel OPl-CPC is preferably again ended by a subfield with an end sequence End, wherein in the case of a periodic repetition of the transmission of the frame and unambiguous identifiability of the beginning of a frame by means of the start field, a transmission of the subfield of the end sequence End may be omitted, if necessary. As an alternative to utilizing a frequency band which is disjoint from the frequency band of the country-specific pilot channel, for transmitting the operator-specific pilot channels, a common frequency spectrum can also be advantageously used, wherein the individual pilot channels can be separated, for example, by means of a respective assignment of one or more subfrequency bands in the sense of an FDMA (Frequency Division Multiple Access) separation and/or by means of further known methods such as, for example, TDMA (Time Division Multiple Access) or CDMA (Code Division Multiple Access). In the same manner, pilot channels can be separated at the country or operator level if an identical frequency band is used for transmissions in adjacent cells. In a subfield following the start field Start, for example, an operator code (OPC) is transmitted by means of which the user terminal UE or another user terminal accessing this pilot channel OP1-CPC can identify the first operator 0P1. In subfields following the subfield of the operator code OPC, information info with respect to the systems or system technologies RAT1, RAT2, ..., RATn (Radio Access Technology) available in the coverage area of the operator-specific pilot channel OP1-CPC including a respective reference to the system specific pilot or control channel or channels RAT1-BCH, RAT2- PCH, ..., RATn-BCH is transmitted. This information enables the user terminal UE, after evaluation and matching with its own technical capabilities, for example with the support of only a number of the available system technologies, to select a suitable system. In accordance with the example of figure 1, the user terminal UE would receive information relating to the systems according to the UMTS and WLAN standard, operated in the coverage area of the pilot channel OPl-CPC, in the pilot channel OPl-CPC of the first operator 0P1, and, for example, select the UMTS system for a first access with the aim of the establishment of a connection. Correspondingly, it shall be assumed in figure 2 that the UMTS system is represented by the first system technology RAT1 being specified. Since the user terminal UE is thus currently located in the coverage area of a radio cell of the UMTS system, an access to this system is possible after evaluation of the reference to the control channel of the UMTS system RATl-BCH. For this purpose, a frame of a control channel of the UMTS system RATl-BCH is shown by way of example on the next hierarchical level, i.e. at the system level, in figure 2. Should the user terminal UE select the WLAN system, however, in the situation shown in figure 1, which is represented by the RAT2 system, technology in figure 2 by way of example, it could RAT2 system technology in figure 2 by way of example, it could not access this pilot channel after evaluation of the reference to the pilot channel of the WLAN system RAT2-PCH since it is currently located outside the coverage area of a radio cell of the WLAN system. In this case, the user terminal UE, after determining that a reception of the pilot channel of the WLAN system RAT2-PCH is not possible, will select, by again accessing the operator-specific pilot channel OP1-CPC, an alternative system, for example the UMTS system identified by the first system technology RAT1 and then access the latter. If this newly selected system is not receivable by the user terminal UE, either, and/or the selected operator does not operate an alternative system which can be used by the user terminal UE, the user terminal UE can again access the country- specific pilot channel C-CPC and select a new operator. The operator-specific pilot channel OP1-CPC with information relating to the systems operated by the respective operator advantageously enables the operator to be able to control, for example, a load distribution between the individual systems. Thus, according to the example of figures 1 and 2, the first operator 0P1, in the case of a full loading or overloading of the WLAN system, could suppress the transmission of information to this system in the pilot channel OP1-CPC, and thus the potential access of user terminals to this system until a load situation is restored which allows further connections to be accepted. As an alternative, the current load situations of the individual operated systems can also be signaled to the user terminals by means of specific information, for example by means of a status indicator in the information info with respect to the system technology. It also appears possible to indicate the distribution of physical resources by changing the information in the subfields of the operator-specific pilot channel in order to achieve, for example, a load balance between systems. If, for example, two systems use a common frequency band within a coverage area, a corresponding reference to a pilot or control channel belonging to this frequency band is signaled in the subfield in dependence on which of the two systems is currently using the frequency band. As a supplement to the references, described above, in the country-specific and the operator-specific pilot channels to the pilot and control channels of the next lower hierarchy level in each case, it may be appropriate also to accommodate a reference to the next higher hierarchy level of the pilot channels. In the example of figure 2, the control channel RAT1-BCH of the UMTS system could thus similarly contain a reference to the pilot channel OP1-CPC of the first operator OP1. By means of this reference, a user terminal UE which maintains an active connection to the UMTS system could directly access the pilot channel of the operator OP1-CPC, for example for preparing an intersystem call forwarding or the establishment of an additional service. In the text which follows, different procedures of the access according to the invention of a user terminal to the different pilot channels or control channels, respectively, are described with reference to the flowchart of figure 3, shown by way of example. Firstly, a first exemplary procedure is described on the basis of the situation that the user terminal UE has no knowledge whatsoever about available systems. This situation occurs, for example, when the user terminal is taken into operation the first time or switched on after a trip outside the homeland. After switch-on or startup, step 0, of the user terminal UE, it will first look for a country-specific pilot channel C-CPC for establishing a connection to a network or system, step 1. If, as explained above, country-specific pilot channels C-CPC are globally sent out in one or more uniform frequency bands, the user terminal UE will tune its receiving device to this frequency band or scan the possible frequency bands for signals of a country-specific pilot channel C-CPC. The frequency band or bands used for the country-specific pilot channel are known to the user terminal UE, for example by the storage of relevant information on the SIM card of the user or a memory of the user terminal. Thus, the transmission method used for the transmission of the pilot channel, for example the coding, modulation, etc., is known to the user terminal UE, so that fast detection and subsequent reception of a country-specific pilot channel C-CPC by the user terminal UE is possible. In the case of a receiving device designed exclusively for the reception of country-specific pilot channels, for example an RDS (Radio Data System) receiver for public broadcast systems, such information is correspondingly not required or only limited to the transmission method. After receiving and evaluating, step 2, of the information transmitted in the country-specific pilot channel C-CPC, the user terminal UE first selects a suitable operator, step 3. This is done in accordance with the methods described above with respect to figures 1 and 2. After evaluation of the country code CC transmitted in the country-specific pilot channel C-CPC, the user terminal UE knows, for example, whether it is located in the coverage area of its home operator or if it must take into consideration roaming agreements between the home operator and foreign operators for the selection of an operator available at the current location of the user terminal. For this purpose, for example, matching with information stored on the SIM card with respect to the home operator and his roaming partner is carried out. If no direct roaming partner is known, the user terminal UE initially optionally selects one of the available operators. This situation will still be described in greater detail in the text which follows. After selecting an operator, the user terminal UE tunes the receiving device to the pilot channel, for example the pilot channel OP1-CPC of the selected first operator OP1. This is done by taking into consideration the reference in the information of the operator-specific subfield of the country-specific pilot channel C-CPC. In dependence on whether the user terminal UE is capable of receiving the pilot channel OP1-CPC of the selected operator, step 4, it will, in the case of adequate receivability of the pilot channel, evaluate its information, step 6, or, in the case of no or only inadequate receivability of the pilot channel, block the selected operator, step 5, and perform a reselection, step 3, of a suitable operator. After evaluating the information of the operator-specific pilot channel, the pilot channel OP1-CPC of the first operator OP1 according to the example of figures 1 and 2, the user terminal UE selects a suitable system or network, step 7. As described above, this selection is carried out, for example, in dependence on the technical equipment of the user terminal or on the service to be set up. After selecting a system or network, the UMTS system according to the example of figures 1 and 2, the user terminal UE tunes the receiving device to the control channel RAT1-BCH in order to receive it and evaluate its content. If the user terminal UE can adequately receive the control channel RATl-BCH and/or the system does not indicate any overload, and thus blocking of the access, step 8, it will receive it and evaluate it, step 10, in order to subsequently carry out an access to the system according to the mechanisms predetermined by the standard of the system. If, in contrast, the user terminal UE is not capable of receiving the control channel RATl-BCH of the selected system, for example because it is currently located outside a radio cell of the system, or overload of the system is indicated, it will block the selected system, step 9, and carry- out a reselection of a suitable system, step 7. If, after an access by the user terminal UE to the selected UMTS system, it is found that it does not support, for example, the desired service to be established, the user terminal UE again carries out a reselection of an alternative system of the operator, the WLAN system according to the example of figures 1 and 2. If, however, no alternative systems of the operator are available or the user terminal UE cannot access the newly selected system, either since, as specified by way of example in figure 1, it is located outside the coverage area or cell of the WLAN system, the user terminal UE carries out a reselection of an alternative operator by again accessing the country- specific pilot channel C-CPC. A further exemplary situation occurs when the user terminal UE already has knowledge of the system last used. This can be available in the form of a storage of connection parameters of the last active connection. In this case, the user terminal UE will first attempt, after switching-on, to receive again the control or pilot channel last used. If this is not possible since the user terminal UE, for example, has changed its location since the last active connection, it will attempt to access the operator-specific pilot channel of the operator last used in order to select a new system or network. For this purpose, it can use, for example, a reference to the operator- specific pilot channel transmitted in the control channel of the system. If this is not possible, either, the user terminal UE will lastly access the country-specific pilot channel C-CPC and progressively select an operator and a system in accordance with the above description. system would take place in supplementary manner in step 4 or 8, respectively, according to the flowchart of figure 3. Relations between individual operators in the sense of roaming agreements are subject to continuous changes. Since, according to the prior art, a list of roaming partners of the home operator is usually stored in the SIM card of a user before the first start-up and is subsequently no longer renewed, it may no longer be valid even after a short time. If, according to the above description, a user terminal is located outside the coverage area of his home operator, it will preferably select, utilizing the country-specific pilot channel, an operator with whom the home operator has concluded a roaming agreement in order to have to pay, for example, lower charges or to be able to use special services. If, however, the user terminal selects an operator with whom there is no longer an agreement due to an outdated list of roaming partners in this situation, the user would incur, for example, disadvantageously higher charges than expected by him. In order to facilitate for the user terminal the choice of an operator with whom there is a roaming agreement and to ensure that the information is up-to-date, it is proposed, according to an embodiment of the invention, to transmit information relating to roaming agreements at the hierarchy level of the country-specific pilot channel C-CPC. In return, this information can be used by the user terminal for updating the stored list of roaming partners, independently of whether the user is located in the area of his home network or not. According to figure 2, the information can be transmitted, for example, by supplementing the information info in the operator- specific subfields of the C-CPC frame. As an alternative, special frames R in the sequence of frames of the country-specific pilot channel C-CPC can be used for transmitting information relating to roaming agreements of the operators listed in the subfields of the country-specific pilot channel C-CPC as shown in figure 4 by way of example. After a sequence of in each case m frames of the country-specific pilot channel C-CPC, for example, one frame R with information relating to roaming agreements is transmitted. The occurrence of the special frame R within the sequence of C-CPC frames can be signaled, for example, in the start fields Start of the C-CPC frames so that a user terminal, if it knows that the next special frame can only be received at a particular time interval, can switch off the receiving device for this period of time and, as a result, advantageously save energy. An exemplary structure of such a frame R with information relating to operator-specific roaming agreements is shown in figure 5a. In accordance with the frame structure of figure 2, a frame R begins with a start field Start R for indicating the beginning of the frame and for identifying this special frame in comparison with the frames of the country-specific pilot channel C-CPC. The start field Start R is followed by a field with information of the country code CC. The subfield following the subfield of the country code CC carries information info relating to, for example, the first operator OP1, wherein this information can largely correspond to the operator information in the normal C-CPC frame. The subfield of the information info relating to the first operator OP1 is followed by subfields with respective information info relating to operators ROP1, . . ., ROPn, with whom the first operator OP1 has concluded a roaming agreement. Corresponding information is transmitted to the second operator 0P2 and his operators ROP1, ..., ROPn connected by roaming agreement. After it has determined by means of the country code that it is located outside the coverage area of its home operator, a user terminal UE receiving this information will look for the code or information with respect to the home operator in the sequence of subfields of frame R and find one or more operators with roaming agreement, which are available within the coverage area of the country-specific pilot channel C-CPC. As an alternative, a frame structure of the special frame R according to figure 5b can also be implemented. According to this exemplary structure, the operators ROP1, ROP2, with whom the operators OP1, ..., OPn available in the coverage area of the country-specific pilot channel C-CPC have roaming agreements, are listed and in each case allocated the available operators OP1, ..., OPn with roaming agreements in subsequent subfields. Due to the rising number of radio access technologies or adaptations to existing technologies, for example in the form of new modulation or coding types, expansion of the frequency spectrum, etc., user terminals will be increasingly equipped as terminals with a so-called software defined radio functionality (SDR) in future. This provides for individual adaptation of the devices of a terminal involved in the radio transmission to the radio access technology required in each case by a purely software-based change. From the German patent specification DE 19734933 C1, for example, a method is known in which, for the purpose of adapting a mobile station to a method of radio access, supported by a mobile radio system, to a pilot channel transmitted by a broadcast transmitting station, information about at least one radio access method of the mobile radio system is transmitted, the pilot channel is received and evaluated by the mobile station and the mobile station selects a radio access method by means of the information and generates an adaptation to this method. For this purpose, the mobile station is referred by means of the signaling, for example to a broadband transmission channel on which program modules are transmitted. These program modules are subsequently used by the mobile station for generating the adaptation. Figure 6 specifies, on the basis of the frame structure of the operator-specific pilot channel OP1-CPC of figure 2, a frame structure by means of which such reconfigurable terminals can be supported in accordance with the method according to the invention. A special subfield DL of the frame contains, for example, information relating to the radio access technologies in each case listed in the text which follows, so that the user terminal, before accessing this radio access technology, can adapt its devices to this technology. This information can be realized, for example, in the form of parameter information but also in the form of complete program modules. As an alternative to a subfield comprising all available access technologies, a separate field can be provided for each access technology or the information info in the subfields can be supplemented by such configuration information. Figure 7, finally, shows by way of example the individual system components which enable the method according to the invention to be realized. The geographic arrangement is based on the example of figure 1. The systems or networks are represented simplified by a respective radio access device, a base station NB (Node B) in the case of the exemplary UMTS system and a so-called access point AP in the case of the exemplary WLAN system. This base station NB or access point AP exhibits, apart from known components and devices, not shown, in each case a transmitting device SE which send out via respective antenna devices signals both of the operator- specific pilot channel OP1-CPC and of the system-specific control BCH (broadcast channel) or PCH (pilot channel), particularly omnidirectionally on the radio interface. By way of example, it is assumed that signals of the country-specific pilot channel C-CPC are emitted by a broadcast transmitting station RFS, for example, of the public broadcast system. As explained above, it is, however, similarly conceivable that the signals of the country-specific pilot channel C-CPC, like the operator-specific pilot channels, are sent out by the base stations or access points of the operator networks. The signals both of the country-specific pilot channel C-CPC and of the operator-specific pilot channel OP1-CPC are received by a receiving device EE of the user terminal UE (user equipment) and evaluated in an evaluating device AW. These devices of the user equipment and a transmitting device SE controlled by the evaluating device AW carry out the access according to the invention to the individual pilot channels and a selection of a suitable operator or system according to the method according to the invention described above. In this context, an involvement of other known devices of the user terminal UE is just as conceivable as that of supplementary devices, for example of a special receiver for signals of the country-specific pilot channel C-CPC sent out by broadcast transmitting stations. Patent claims 1. A method for the establishment of a connection in a radio communication system, wherein a user terminal (UE) - selects an operator (OP1) on the basis of information (info), transmitted in a country-specific pilot channel (C-CPC), on at least one operator (OP1, 0P2) of a radio communication system, - on the basis of information (info), transmitted in an operator-specific pilot channel (OP1-CPC) of the selected operator (OP1), on at least one radio communication system, selects a radio communication system (RAT1, UMTS) and - carries out an access to the selected radio communication system (RAT1, UMTS) for the establishment of a connection. 2. The method as claimed in claim 1, in which a reference to at least the operator-specific pilot channel (OP1-CPC) is transmitted as information (info) in the country-specific pilot channel (C-CPC). 3. The method as claimed in claim 1 or 2, in which a reference to at least one system-specific pilot channel (RAT1-BCH) of the at least one radio communication system (RAT1, UMTS) is transmitted as information (info) in the operator-specific pilot channel (OP1-CPC). 4. The method as claimed in claim 3, wherein information of a synchronization channel, control channel and/or pilot channel is transmitted in the system-specific pilot channel (RAT1-BCH). 5. The method as claimed in claim 3 or 4, in which the at least one operator-specific pilot channel (OP1-CPC) and the at least one system-specific pilot channel (RAT1-BCH) are sent out by at least one radio access device (NB, AP) of the at least one radio communication system. 6. The method as claimed in a preceding claim, in which the country-specific pilot channel (C-CPC) is sent out by at least one radio access device (NB, AP) of the at least one radio communication system and/or a broadcast transmitting station (RFS) of a public or private broadcasting system. 7. The method as claimed in a preceding claim, in which information (info) on operators (ROP1, ROPn), with whom the at least one operator (OP1) maintains national and/or international roaming agreements, is transmitted in the country-specific pilot channel (C-CPC). 8. The method as claimed in claim 7, in which the information (info) on operators (ROP1, ROPn) with roaming agreements is transmitted in specific frames (R) within a sequence of frames of the country-specific pilot channel (C-CPC). 9. The method as claimed in a preceding claim, in which information (DL) with respect to a system-specific configuration of the user terminal (UE) is transmitted in the operator-specific pilot channel (OP1-CPC). 10. A method for operating a radio communication system, in which signals of at least one country-specific pilot channel (C-CPC) with information (info) on at least one operator (OP1, OP2) of a radio communication system, of at least one operator-specific pilot channel (OP1-CPC) with information (info) on at least one radio communication system (RAT1, UMTS, WLAN) and of at least one system-specific pilot channel (RAT1-BCH) are sent out by at least one radio access device (NB, AP) of the radio communication system. 11. A radio communication system having at least one radio access device (NB, AP) comprising at least one transmitting device (SE) for sending out signals of at least one country-specific pilot channel (C-CPC) with information (info) on at least one operator (OP1, 0P2) of a radio communication system, of at least one operator-specific pilot channel (OP1-CPC) with information (info) on at least one radio communication system (RAT1, UMTS, WLAN) and of at least one system-specific pilot channel (RAT1-BCH). 12. A user terminal (UE) having at least - one receiving device (EE) for receiving at least one country- specific pilot channel (C-CPC), one operator-specific pilot channel (OP1-CPC) and one system-specific pilot channel (RAT1-BCH), - one evaluating device (AW) for evaluating information (info) of the received at least one country-specific pilot channel (C-CPC) with respect to at least one operator (OP1, OP2, ..., OPn) and for selecting an operator (OP1), for evaluating information (info) of the received operator-specific pilot channel (OP1-CPC) of the selected operator (OP1) and for selecting a radio communication system (RAT1, UMTS) and for evaluating information of the received system-specific pilot channel (RAT1-BCH) of the selected radio communication system (RAT1, UMTS) and for deciding on an access to the selected radio communication system (RAT1, UMTS), and - one transmitting device (SE) for sending out signals for an access to the selected radio communication system (RAT1, UMTS). The invention relates to a method for establishment of a connection in a radio communication system, wherein a user terminal (UE) selects an operator (OPI), based on information (info) on at least one operator (OPI,OP2) of a radio communication system in a country-specific pilot channel (C-CPC), selects a radio communication system (RATI,IMTS) based on information (info) on at least one radio communication system in an operator-secific pilot channel (OPI-CPC) for the selected operator (OPI) and carries out an access to the selected radio communication system (RATI,UMTS) for establishment of a connection.

Full Text

Description
ESTABLISHMENT OF A CONNECTION IN RADIO COMMUNICATION SYSTEMS
The invention relates to a method for the establishment of a
connection in radio communication systems, particularly in
mobile radio systems, and to components of the radio
communication system for carrying out the method according to
the invention.
A continuously rising number of different radio communication
systems, to mention only the systems according to the familiar
GSM, IS-95, UMTS, CDMA2000, WLAN, WiMAX, etc. standards, for
example, leads to user terminals also supporting an ever
increasing number of these systems or standards and, as a
result, providing the user with access to communication
networks in the most varied manner. In addition, operators of
radio communication systems are increasingly providing their
customers with systems of different standards, with the
possibility of roaming between these systems.
However, all this can disadvantageously lead to the period for
establishing a connection by a user terminal being extended due
to the large selection of available systems which, in addition,
operate in different system-specific frequency bands, as a
rule. If, for example, the user wishes to use a high-data-rate
service, to mention video streaming as an example, such a
service can be potentially provided by different systems. If no
specific system has been preselected by the user, the user
terminal, during the establishment of the connection,
establishes contact to various systems or, respectively, the
user terminal first attempts to receive signals from different
systems - for example of the same operator - and then to select
a system suitable for the selected service.

Especially when the user terminal is taken into operation at a
location which it has previously not maintained a connection to
a system and can thus not make use of empirical values, for
example if the user is located in a foreign country after a
flight, an additional aggravating factor which may extend the
access time is that the local operator is not known, with whom
the home operator has concluded a so-called roaming agreement
in order to provide lowered connection charges to the customer.
In this case, a local system or operator may be proposed to the
user a number of times, with which the user must then decide
whether a connection establishment is to take place or not.
From DE 197 34 933 C1, a method is known in which a mobile
station located in a radio coverage area of a mobile radio
network generates an adaptation to an air interface access
method of the mobile radio network by signaling information
transmitted on a pilot channel. In this context, the pilot
channel is transmitted by at least one broadcast transmitting
station of a public broadcasting system in the radio coverage
area of the mobile radio network and received and evaluated by
the mobile station.
To provide an overview of the increasing number of systems for
users or user terminals, it has already been proposed, inter
alia in the document "Global Pilot Mechanism" Tdoc SMG2 UMTS
52/97, ETSI STC SMG2 UMTS adhoc, April 8-10, 1997, Lulea,
Sweden, pages 1 and 2, to introduce a globally uniform pilot
channel (Global Pilot Channel) on a uniform frequency channel
or in a uniform frequency spectrum. On such a global pilot
channel, information about the respective locally available
radio access technologies (Radio Access Technology Indicator)
and references (Spectral Pointers) to their spectral position
should be transmitted so that a user terminal can select and
access a suitable or supported radio access technology.

Radio access technologies are understood to be systems of
different standards, for example GSM and UMTS which operate in
different frequency bands. According to the above document, the
pilot channel should be sent out either by the operators
themselves which would correspondingly also have to send out
information by competing operators, or by a national entity not
specified in greater detail, for example the regulating
authority.

However, such a uniform pilot channel has the disadvantage that
with the rising number of different systems and their expansion
to a greater number of frequency bands, the signaling load
would also rise continuously. In addition, the administrative
effort for acquiring and sending out information of the
different systems appears to be comparatively large.
Furthermore, a user terminal, after having been referred to the
frequency spectrum, for example of the GSM mobile radio system,
by means of the pilot channel, would still have to perform a
large number of measurements of networks of different operators
in order to find an operator network which is suitable for the
desired service or the desired tariff or contract.
It is the object of the invention, therefore, to specify a
method, a system and system components which enable a user
terminal to establish a connection setup to a desired radio
communication system or network in a simple and quick manner.
This object is achieved by the features of the independent
patent claims. Advantageous embodiments of the invention can be
found in dependent patent claims.
According to the invention, a user terminal selects an operator
on the basis of information on at least one operator of a radio
communication system in a country-specific pilot channel.
Following this, the user terminal selects a radio communication
system on the basis of information on at least one radio
communication system in an operator-specific pilot channel of
the selected operator and, finally, carries out an access to
the selected radio communication system for the establishment
of a connection.
Advantageously, the hierarchical structure of the pilot
channels according to the invention and a corresponding
subdivision of the information in each case transmitted in the
pilot channels provides for a simpler and more flexible
administration of the contents of

the pilot channels compared with the method of the prior art,
described by way of the introduction. Thus, for example, a
change of the systems or networks supported by an operator does
not require any change in the content of the country-specific
pilot channel which, if necessary, is administered by a higher-
level entity, for example a national regulating authority.
Advantageously, the respective operator can also dynamically
change, for example the assignment of physical resources to the
individual systems or networks in the sense of a dynamic
resource assignment in the pilot channel allocated to him, for
example in order to optimize a load distribution in the systems
or networks. In this context, the content of the operator-
specific pilot channel is advantageously configured, for
example, by the operator himself, for example by means of a
correspondingly designed operation and maintenance function
(O&M). If a number of operators use the same frequency
spectrum, the current use and its corresponding signaling
should preferably take place in agreement with one another on
the operator-specific pilot channels.
In the same manner, the user terminal is advantageously enabled
to pass through a uniform connection setup procedure in order
to carry out a quick establishment of a connection to a desired
system or network independently of its current location.
According to a further development of the invention, a
reference to at least the operator-specific pilot channel is
transmitted as information in the country-specific pilot
channel. By means of this information, the user terminal can
directly access the operator-specific pilot channel. The same
applies to another development according to which a reference
to at least one system-specific pilot channel of the at least
one radio communication system is transmitted as information in
the operator-specific pilot channel.

In accordance with a further embodiment of the method according
to the invention, information of a synchronization channel,
control channel and/or pilot channel is transmitted in the
system-specific pilot channel. In this context, the information
is dependent on the respective configuration of the radio
interface or the radio transmission standard, respectively, and
can have a different content in dependence on the system or
standard.
According to a further embodiment, the at least one operator-
specific pilot channel and the at least one system-specific
pilot channel are sent out by at least one radio access device
of the at least one radio communication system. This has the
advantageous effect that the number of devices involved in the
sending out of the pilot channels is limited. According to a
further development, the country-specific pilot channel is also
sent out by at least one radio access device of the at least one
radio communication system and/or a broadcast transmitting
station of a public or private broadcasting system. Using
broadcast transmitting stations offers the advantage that, by
using facilities which are already in existence, large
geographic areas can be covered with one radio cell. In this
context, long transit times which may be due to the size of the
radio cell do not have a negative effect since the signal
transmission is exclusively in the downward direction, i.e. in
the direction of the user terminals.
According to a further development of the invention, information
on operators, with whom the at least one operator maintains
national and/or international roaming agreements, is
additionally transmitted in the country-specific pilot channel.
This enables a user terminal which is located outside its own
network to obtain in a simple manner an overview of the locally
available operators and finally to select one operator.
According to a further development, the

information on operators with roaming agreements can be
transmitted in specific frames

within a sequence of frames of the country-specific pilot
channel.
According to a further embodiment of the invention, finally, a
reconfigurability of the user terminal by means of a
transmission of information with respect to a system-specific
configuration of the user terminal in the operator-specific
pilot channel is supported, as a result of which the user
terminal can be advantageously adapted to the radio access
method of the selected system even before an access to the
system.
The system according to the invention and system components in
each case have devices according to the invention by means of
which the method according to the invention can be realized.
In the text which follows, the invention will be presented in
greater detail by means of an exemplary embodiment, in which:
figure 1 shows a representation of coverage areas of
respective pilot channels,
figure 2 shows a representation of the hierarchical structure
of the pilot channels and their contents,
figure 3 shows a flowchart of an access of a user terminal to
a system,
figure 4 shows a sequence of frames of a country-specific
pilot channel,
figures 5a, 5b show structures of frames with information with
respect to operators with roaming agreements,
figure 6 shows the structure of an operator-specific frame
with a subfield for reconfigurable terminals, and
figure 7 shows a representation of system components.
Figure 1 shows by way of example the respective coverage areas
of the pilot channels according to the invention. It shall be

assumed in this context that a country-specific pilot channel
C-CPC (Country level Common Pilot Channel) radiates information

channel C-CPC by means of broadcast transmitting stations, it
can also be sent out by the systems of the operators
themselves.
Apart from the first operator 0P1 operating nationwide,
figure 1 also shows by way of example the coverage area of a
second, locally operating operator 0P2 with three radio cells
of a wireless access system according to the so-called WiMAX
standard (IEEE 802.16).
Furthermore, a user terminal UE which is located in the
coverage area of systems and networks both of the first
operator OP1 and of the second operator OP2, and is thus
potentially capable of establishing a connection to each of
these systems, is shown by way of example. For subsequent
explanations it shall be assumed that the user terminal UE is
technically constructed to support the three standards
mentioned by way of example, wherein the method can be
similarly carried out for user terminals which only support one
of the standards.
In the exemplary situation of figure 1, it shall also be
assumed that the user terminal UE is switched on or taken into
operation for the first time. This occurs, for example, after
the purchase of the terminal by the user or after arrival at
the airport after a trip from another country. To establish a
first contact to a system operating at the location of the user
terminal, the user terminal will first tune itself to the
frequency band of the country-specific pilot channel C-CPC,
receive it and evaluate information contained therein and then
select a suitable or predetermined operator, for example on the
basis of operator information or roaming agreements of
operators stored in the SIM card. As mentioned before, the
frequency band and the access technology of the country-
specific pilot channel C-CPC is preferably known per se to the

user terminal UE so that the country-specific pilot channel
C-CPC can be selectively and rapidly accessed.

On the basis of the information contained in the country-
specific pilot channel C-CPC, the user terminal UE thus selects
a suitable or predetermined operator and subsequently tunes the
receiving device to the operator-specific pilot channel of the
selected operator by means of a reference contained in the
information of the country-specific pilot channel C-CPC.
A cellular structure, described above, of the country-specific
pilot channel advantageously enables regional or local
peculiarities to be taken into consideration and, as a result,
to limit the volume of information to be transmitted in the
pilot channel. Thus, for example, in the case where an operator
operates in a locally limited way and thus exclusively in one
particular one of the multiplicity of cells of the country-
specific pilot channel, information and a reference to this
operator could be sent out exclusively in this cell whereas no
information whatsoever relating to this operator is sent out in
all other cells of the country-specific pilot channel in which
this operator is not operating. This would correspondingly
apply if an operator, for example, operates wireless access
networks exclusively in metropolitan areas. In this case, it
would be sufficient that only the cells of the country-specific
pilot channel which comprise the metropolitan areas affected
send out information and references to this operator.
In the operator-specific pilot channel, in turn, information
with respect to the systems and networks supported by the
operator is transmitted so that the user terminal UE can
subsequently select and access a suitable system or network,
respectively. The user terminal UE is preferably again referred
to the selected system or network by means of a reference to a
system-specific pilot channel, synchronization channel or
control channel contained in the information of the operator-
specific pilot channel. In the text which follows, the term
pilot channel will be used as synonym for

such system-specific channels. In this context, the operator-
specific pilot channel is transmitted, corresponding to the
country-specific pilot channel, preferably in a uniform
frequency band, for example in a subfrequency band of the
country-specific pilot channel in order to provide for rapid
access by the user terminal wherein, as an alternative, a
limited number of frequency bands also appears to be possible
and appropriate, in turn.
Figure 2 shows by way of example the hierarchical structure
according to the invention of the pilot channels and a
respective exemplary frame structure, referring to the
situation of figure 1.
The country-specific pilot channel C-CPC is composed, for
example, of the several subfields of different content, shown
in figure 2, wherein these subfields can also be transmitted in
a different order in the sense of the invention. Together, the
subfields produce a frame which is sent out periodically as
mentioned above, for example by broadcast transmitting stations
or operator stations.
The beginning of a frame is identified by a start field or
starting sequence Start. This Start field can contain
information about the identity of the pilot channel, for
example with regard to the fact that this is a country-specific
pilot channel, in contrast to an operator-specific pilot
channel, but also a synchronization sequence which enables a
user terminal to synchronize itself to the transmission in the
pilot channel, and for detecting the beginning of a respective
frame.
In a second subfield, following the start field start, of the
country-specific pilot channel C-CPC, a country code (CC) is
preferably transmitted on the basis of which the receiving user
terminal UE can identify the country

in the territorial field of which it is currently located. This
country code CC can be used by the user terminal, for example,
for matching it with information, stored on the SIM card or an
integrated memory, relating to operators of this country, for
example with respect to existing roaming agreements.
Following the second subfield of the country code CC,
information info with respect to the operators OP1, OP2, ...,
OPn operating in the coverage area of the country-specific
pilot channel C-CPC, including a respective reference to the
operator-specific pilot channel or channels OP1-CPC, OP2-CPC,
..., OPn-CPC (Operator level Common Pilot Channel) is
transmitted in respective subfields. This information enables
the user terminal UE, after evaluation and the abovementioned
matching, to select a suitable operator, the first operator 0P1
in the example of figure 2, and to directly access the pilot
channel or channels OP1-CPC of this selected first operator OP1
by means of the reference.
Finally, a frame of the country-specific pilot channel C-CPC is
preferably concluded by a subfield with an end sequence End. In
the case of a periodic repetition of the transmission of the
frame and unambiguous identifiability of the beginning of a
frame by means of the start field, however, a transmission of
the subfield of the end sequence End can also be omitted,
however.
At the hierarchy level of the operator, a corresponding frame
structure of a pilot channel is used but with at least
partially different content of the subfields. The operator-
specific pilot channel is also preferably periodically
repeatedly sent out. Figure 2 shows by way of example the frame
structure of the operator-specific pilot channel OPl-CPC of the
first operator 0P1 selected by the user terminal UE.

Since, as a rule, the operator-specific pilot channel OP1-CPC
is sent out in a frequency band disjoint from the country-
specific pilot channel C-CPC, an identification of the
beginning of a respective frame by means of a start field Start
is again appropriate. Corresponding to the described field of
the country-specific pilot channel C-CPC, this Start field can
again contain information about the identity of the pilot
channel, for example with regard to the fact that this is an
operator-specific pilot channel, in contrast to the country-
specific pilot channel C-CPC, but also a synchronization
sequence which enables a user terminal to synchronize itself to
the transmissions in the pilot channel. A frame of the
operator-specific pilot channel OPl-CPC is preferably again
ended by a subfield with an end sequence End, wherein in the
case of a periodic repetition of the transmission of the frame
and unambiguous identifiability of the beginning of a frame by
means of the start field, a transmission of the subfield of the
end sequence End may be omitted, if necessary.
As an alternative to utilizing a frequency band which is
disjoint from the frequency band of the country-specific pilot
channel, for transmitting the operator-specific pilot channels,
a common frequency spectrum can also be advantageously used,
wherein the individual pilot channels can be separated, for
example, by means of a respective assignment of one or more
subfrequency bands in the sense of an FDMA (Frequency Division
Multiple Access) separation and/or by means of further known
methods such as, for example, TDMA (Time Division Multiple
Access) or CDMA (Code Division Multiple Access). In the same
manner, pilot channels can be separated at the country or
operator level if an identical frequency band is used for
transmissions in adjacent cells.
In a subfield following the start field Start, for example, an
operator code (OPC) is transmitted

by means of which the user terminal UE or another user terminal
accessing this pilot channel OP1-CPC can identify the first
operator 0P1.
In subfields following the subfield of the operator code OPC,
information info with respect to the systems or system
technologies RAT1, RAT2, ..., RATn (Radio Access Technology)
available in the coverage area of the operator-specific pilot
channel OP1-CPC including a respective reference to the system
specific pilot or control channel or channels RAT1-BCH, RAT2-
PCH, ..., RATn-BCH is transmitted. This information enables the
user terminal UE, after evaluation and matching with its own
technical capabilities, for example with the support of only a
number of the available system technologies, to select a
suitable system.
In accordance with the example of figure 1, the user terminal
UE would receive information relating to the systems according
to the UMTS and WLAN standard, operated in the coverage area of
the pilot channel OPl-CPC, in the pilot channel OPl-CPC of the
first operator 0P1, and, for example, select the UMTS system
for a first access with the aim of the establishment of a
connection. Correspondingly, it shall be assumed in figure 2
that the UMTS system is represented by the first system
technology RAT1 being specified. Since the user terminal UE is
thus currently located in the coverage area of a radio cell of
the UMTS system, an access to this system is possible after
evaluation of the reference to the control channel of the UMTS
system RATl-BCH. For this purpose, a frame of a control channel
of the UMTS system RATl-BCH is shown by way of example on the
next hierarchical level, i.e. at the system level, in figure 2.
Should the user terminal UE select the WLAN system, however, in
the situation shown in figure 1, which is represented by the
RAT2 system, technology in figure 2 by way of example, it could
RAT2 system technology in figure 2 by way of example, it could

not access this pilot channel after evaluation of the reference
to the pilot channel of the WLAN system RAT2-PCH

since it is currently located outside the coverage area of a
radio cell of the WLAN system. In this case, the user terminal
UE, after determining that a reception of the pilot channel of
the WLAN system RAT2-PCH is not possible, will select, by again
accessing the operator-specific pilot channel OP1-CPC, an
alternative system, for example the UMTS system identified by
the first system technology RAT1 and then access the latter. If
this newly selected system is not receivable by the user
terminal UE, either, and/or the selected operator does not
operate an alternative system which can be used by the user
terminal UE, the user terminal UE can again access the country-
specific pilot channel C-CPC and select a new operator.
The operator-specific pilot channel OP1-CPC with information
relating to the systems operated by the respective operator
advantageously enables the operator to be able to control, for
example, a load distribution between the individual systems.
Thus, according to the example of figures 1 and 2, the first
operator 0P1, in the case of a full loading or overloading of
the WLAN system, could suppress the transmission of information
to this system in the pilot channel OP1-CPC, and thus the
potential access of user terminals to this system until a load
situation is restored which allows further connections to be
accepted. As an alternative, the current load situations of the
individual operated systems can also be signaled to the user
terminals by means of specific information, for example by
means of a status indicator in the information info with
respect to the system technology.
It also appears possible to indicate the distribution of
physical resources by changing the information in the subfields
of the operator-specific pilot channel in order to achieve, for
example, a load balance between systems. If, for example, two
systems use a common frequency band within a coverage area,

a corresponding reference to a pilot or control channel
belonging to this frequency band is signaled in the subfield in
dependence on which of the two systems is currently using the
frequency band.
As a supplement to the references, described above, in the
country-specific and the operator-specific pilot channels to
the pilot and control channels of the next lower hierarchy
level in each case, it may be appropriate also to accommodate a
reference to the next higher hierarchy level of the pilot
channels. In the example of figure 2, the control channel
RAT1-BCH of the UMTS system could thus similarly contain a
reference to the pilot channel OP1-CPC of the first operator
OP1. By means of this reference, a user terminal UE which
maintains an active connection to the UMTS system could
directly access the pilot channel of the operator OP1-CPC, for
example for preparing an intersystem call forwarding or the
establishment of an additional service.
In the text which follows, different procedures of the access
according to the invention of a user terminal to the different
pilot channels or control channels, respectively, are described
with reference to the flowchart of figure 3, shown by way of
example.
Firstly, a first exemplary procedure is described on the basis
of the situation that the user terminal UE has no knowledge
whatsoever about available systems. This situation occurs, for
example, when the user terminal is taken into operation the
first time or switched on after a trip outside the homeland.
After switch-on or startup, step 0, of the user terminal UE, it
will first look for a country-specific pilot channel C-CPC for
establishing a connection to a network or system, step 1. If,
as explained above, country-specific pilot channels C-CPC are
globally

sent out in one or more uniform frequency bands, the user
terminal UE will tune its receiving device to this frequency
band or scan the possible frequency bands for signals of a
country-specific pilot channel C-CPC. The frequency band or
bands used for the country-specific pilot channel are known to
the user terminal UE, for example by the storage of relevant
information on the SIM card of the user or a memory of the user
terminal. Thus, the transmission method used for the
transmission of the pilot channel, for example the coding,
modulation, etc., is known to the user terminal UE, so that
fast detection and subsequent reception of a country-specific
pilot channel C-CPC by the user terminal UE is possible. In the
case of a receiving device designed exclusively for the
reception of country-specific pilot channels, for example an
RDS (Radio Data System) receiver for public broadcast systems,
such information is correspondingly not required or only
limited to the transmission method.
After receiving and evaluating, step 2, of the information
transmitted in the country-specific pilot channel C-CPC, the
user terminal UE first selects a suitable operator, step 3.
This is done in accordance with the methods described above
with respect to figures 1 and 2. After evaluation of the
country code CC transmitted in the country-specific pilot
channel C-CPC, the user terminal UE knows, for example, whether
it is located in the coverage area of its home operator or if
it must take into consideration roaming agreements between the
home operator and foreign operators for the selection of an
operator available at the current location of the user
terminal. For this purpose, for example, matching with
information stored on the SIM card with respect to the home
operator and his roaming partner is carried out. If no direct
roaming partner is known, the user terminal UE initially
optionally selects

one of the available operators. This situation will still be
described in greater detail in the text which follows.
After selecting an operator, the user terminal UE tunes the
receiving device to the pilot channel, for example the pilot
channel OP1-CPC of the selected first operator OP1. This is done
by taking into consideration the reference in the information of
the operator-specific subfield of the country-specific pilot
channel C-CPC. In dependence on whether the user terminal UE is
capable of receiving the pilot channel OP1-CPC of the selected
operator, step 4, it will, in the case of adequate receivability
of the pilot channel, evaluate its information, step 6, or, in
the case of no or only inadequate receivability of the pilot
channel, block the selected operator, step 5, and perform a
reselection, step 3, of a suitable operator.
After evaluating the information of the operator-specific pilot
channel, the pilot channel OP1-CPC of the first operator OP1
according to the example of figures 1 and 2, the user terminal
UE selects a suitable system or network, step 7. As described
above, this selection is carried out, for example, in
dependence on the technical equipment of the user terminal or
on the service to be set up. After selecting a system or
network, the UMTS system according to the example of figures 1
and 2, the user terminal UE tunes the receiving device to the
control channel RAT1-BCH in order to receive it and evaluate
its content. If the user terminal UE can adequately receive the
control channel RATl-BCH and/or the system does not indicate
any overload, and thus blocking of the access, step 8, it will
receive it and evaluate it, step 10, in order to subsequently
carry out an access to the system according to the mechanisms
predetermined by the standard of the system. If, in contrast,
the user terminal UE is not capable of receiving the control
channel RATl-BCH of the selected system, for example because it
is currently located

outside a radio cell of the system, or overload of the system
is

indicated, it will block the selected system, step 9, and carry-
out a reselection of a suitable system, step 7.
If, after an access by the user terminal UE to the selected
UMTS system, it is found that it does not support, for example,
the desired service to be established, the user terminal UE
again carries out a reselection of an alternative system of the
operator, the WLAN system according to the example of figures 1
and 2. If, however, no alternative systems of the operator are
available or the user terminal UE cannot access the newly
selected system, either since, as specified by way of example
in figure 1, it is located outside the coverage area or cell of
the WLAN system, the user terminal UE carries out a reselection
of an alternative operator by again accessing the country-
specific pilot channel C-CPC.
A further exemplary situation occurs when the user terminal UE
already has knowledge of the system last used. This can be
available in the form of a storage of connection parameters of
the last active connection. In this case, the user terminal UE
will first attempt, after switching-on, to receive again the
control or pilot channel last used. If this is not possible
since the user terminal UE, for example, has changed its
location since the last active connection, it will attempt to
access the operator-specific pilot channel of the operator last
used in order to select a new system or network. For this
purpose, it can use, for example, a reference to the operator-
specific pilot channel transmitted in the control channel of
the system. If this is not possible, either, the user terminal
UE will lastly access the country-specific pilot channel C-CPC
and progressively select an operator and a system in accordance
with the above description.

system would take place in supplementary manner in step 4 or 8,
respectively, according to the flowchart of figure 3.
Relations between individual operators in the sense of roaming
agreements are subject to continuous changes. Since, according
to the prior art, a list of roaming partners of the home
operator is usually stored in the SIM card of a user before the
first start-up and is subsequently no longer renewed, it may no
longer be valid even after a short time. If, according to the
above description, a user terminal is located outside the
coverage area of his home operator, it will preferably select,
utilizing the country-specific pilot channel, an operator with
whom the home operator has concluded a roaming agreement in
order to have to pay, for example, lower charges or to be able
to use special services. If, however, the user terminal selects
an operator with whom there is no longer an agreement due to an
outdated list of roaming partners in this situation, the user
would incur, for example, disadvantageously higher charges than
expected by him.
In order to facilitate for the user terminal the choice of an
operator with whom there is a roaming agreement and to ensure
that the information is up-to-date, it is proposed, according
to an embodiment of the invention, to transmit information
relating to roaming agreements at the hierarchy level of the
country-specific pilot channel C-CPC. In return, this
information can be used by the user terminal for updating the
stored list of roaming partners, independently of whether the
user is located in the area of his home network or not.
According to figure 2, the information can be transmitted, for
example, by supplementing the information info in the operator-
specific subfields of the C-CPC frame. As an alternative,
special frames R in the sequence of frames

of the country-specific pilot channel C-CPC can be used for
transmitting information relating to roaming agreements of the
operators listed in the subfields of the country-specific pilot
channel C-CPC as shown in figure 4 by way of example. After a
sequence of in each case m frames of the country-specific pilot
channel C-CPC, for example, one frame R with information
relating to roaming agreements is transmitted. The occurrence
of the special frame R within the sequence of C-CPC frames can
be signaled, for example, in the start fields Start of the
C-CPC frames so that a user terminal, if it knows that the next
special frame can only be received at a particular time
interval, can switch off the receiving device for this period
of time and, as a result, advantageously save energy.
An exemplary structure of such a frame R with information
relating to operator-specific roaming agreements is shown in
figure 5a. In accordance with the frame structure of figure 2,
a frame R begins with a start field Start R for indicating the
beginning of the frame and for identifying this special frame
in comparison with the frames of the country-specific pilot
channel C-CPC. The start field Start R is followed by a field
with information of the country code CC. The subfield following
the subfield of the country code CC carries information info
relating to, for example, the first operator OP1, wherein this
information can largely correspond to the operator information
in the normal C-CPC frame. The subfield of the information info
relating to the first operator OP1 is followed by subfields
with respective information info relating to operators ROP1,
. . ., ROPn, with whom the first operator OP1 has concluded a
roaming agreement. Corresponding information is transmitted to
the second operator 0P2 and his operators ROP1, ..., ROPn
connected by roaming agreement. After it has determined by
means of the country code that it is located outside the
coverage area of its home operator, a user terminal UE
receiving this information will look for the code or
information with respect to the home operator in the sequence

of subfields of frame R and find one or more operators with
roaming agreement, which are available within the coverage area

of the country-specific pilot channel C-CPC.
As an alternative, a frame structure of the special frame R
according to figure 5b can also be implemented. According to
this exemplary structure, the operators ROP1, ROP2, with whom
the operators OP1, ..., OPn available in the coverage area of
the country-specific pilot channel C-CPC have roaming
agreements, are listed and in each case allocated the available
operators OP1, ..., OPn with roaming agreements in subsequent
subfields.
Due to the rising number of radio access technologies or
adaptations to existing technologies, for example in the form
of new modulation or coding types, expansion of the frequency
spectrum, etc., user terminals will be increasingly equipped as
terminals with a so-called software defined radio functionality
(SDR) in future. This provides for individual adaptation of the
devices of a terminal involved in the radio transmission to the
radio access technology required in each case by a purely
software-based change.
From the German patent specification DE 19734933 C1, for
example, a method is known in which, for the purpose of
adapting a mobile station to a method of radio access,
supported by a mobile radio system, to a pilot channel
transmitted by a broadcast transmitting station, information
about at least one radio access method of the mobile radio
system is transmitted, the pilot channel is received and
evaluated by the mobile station and the mobile station selects
a radio access method by means of the information and generates
an adaptation to this method. For this purpose, the mobile
station is referred by means of the signaling, for example to a
broadband transmission channel on which program modules are
transmitted. These program modules are subsequently used by the
mobile station for generating the adaptation.

Figure 6 specifies, on the basis of the frame structure of the
operator-specific pilot channel OP1-CPC of figure 2, a frame
structure by means of which such reconfigurable terminals can
be supported in accordance with the method according to the
invention. A special subfield DL of the frame contains, for
example, information relating to the radio access technologies
in each case listed in the text which follows, so that the user
terminal, before accessing this radio access technology, can
adapt its devices to this technology. This information can be
realized, for example, in the form of parameter information but
also in the form of complete program modules. As an alternative
to a subfield comprising all available access technologies, a
separate field can be provided for each access technology or
the information info in the subfields can be supplemented by
such configuration information.
Figure 7, finally, shows by way of example the individual
system components which enable the method according to the
invention to be realized. The geographic arrangement is based
on the example of figure 1. The systems or networks are
represented simplified by a respective radio access device, a
base station NB (Node B) in the case of the exemplary UMTS
system and a so-called access point AP in the case of the
exemplary WLAN system. This base station NB or access point AP
exhibits, apart from known components and devices, not shown,
in each case a transmitting device SE which send out via
respective antenna devices signals both of the operator-
specific pilot channel OP1-CPC and of the system-specific
control BCH (broadcast channel) or PCH (pilot channel),
particularly omnidirectionally on the radio interface. By way
of example, it is assumed that signals of the country-specific
pilot channel C-CPC are emitted by a broadcast transmitting
station RFS, for example, of the public broadcast system. As
explained above, it is, however, similarly conceivable that the

signals of the country-specific pilot channel C-CPC, like the
operator-specific pilot channels, are sent out by the base
stations or access points of the operator networks.
The signals both of the country-specific pilot channel C-CPC
and of the operator-specific pilot channel OP1-CPC are received
by a receiving device EE of the user terminal UE (user
equipment) and evaluated in an evaluating device AW. These
devices of the user equipment and a transmitting device SE
controlled by the evaluating device AW carry out the access
according to the invention to the individual pilot channels and
a selection of a suitable operator or system according to the
method according to the invention described above. In this
context, an involvement of other known devices of the user
terminal UE is just as conceivable as that of supplementary
devices, for example of a special receiver for signals of the
country-specific pilot channel C-CPC sent out by broadcast
transmitting stations.

Patent claims
1. A method for the establishment of a connection in a radio
communication system, wherein a user terminal (UE)
- selects an operator (OP1) on the basis of information (info),
transmitted in a country-specific pilot channel (C-CPC), on at
least one operator (OP1, 0P2) of a radio communication system,
- on the basis of information (info), transmitted in an
operator-specific pilot channel (OP1-CPC) of the selected
operator (OP1), on at least one radio communication system,
selects a radio communication system (RAT1, UMTS) and
- carries out an access to the selected radio communication
system (RAT1, UMTS) for the establishment of a connection.

2. The method as claimed in claim 1, in which a reference to
at least the operator-specific pilot channel (OP1-CPC) is
transmitted as information (info) in the country-specific pilot
channel (C-CPC).
3. The method as claimed in claim 1 or 2, in which a
reference to at least one system-specific pilot channel
(RAT1-BCH) of the at least one radio communication system
(RAT1, UMTS) is transmitted as information (info) in the
operator-specific pilot channel (OP1-CPC).
4. The method as claimed in claim 3, wherein information of a
synchronization channel, control channel and/or pilot channel
is transmitted in the system-specific pilot channel (RAT1-BCH).
5. The method as claimed in claim 3 or 4, in which the at
least one operator-specific pilot channel (OP1-CPC) and the at
least one system-specific pilot channel (RAT1-BCH) are sent out
by at least one radio access device (NB, AP) of the at least
one radio communication system.

6. The method as claimed in a preceding claim, in which the
country-specific pilot channel (C-CPC) is sent out by at least
one radio access device (NB, AP) of the at least one radio
communication system and/or a broadcast transmitting station
(RFS) of a public or private broadcasting system.
7. The method as claimed in a preceding claim, in which
information (info) on operators (ROP1, ROPn), with whom the at
least one operator (OP1) maintains national and/or
international roaming agreements, is transmitted in the
country-specific pilot channel (C-CPC).
8. The method as claimed in claim 7, in which the information
(info) on operators (ROP1, ROPn) with roaming agreements is
transmitted in specific frames (R) within a sequence of frames
of the country-specific pilot channel (C-CPC).
9. The method as claimed in a preceding claim, in which
information (DL) with respect to a system-specific
configuration of the user terminal (UE) is transmitted in the
operator-specific pilot channel (OP1-CPC).
10. A method for operating a radio communication system, in
which
signals of at least one country-specific pilot channel (C-CPC)
with information (info) on at least one operator (OP1, OP2) of
a radio communication system, of at least one operator-specific
pilot channel (OP1-CPC) with information (info) on at least one
radio communication system (RAT1, UMTS, WLAN) and of at least
one system-specific pilot channel (RAT1-BCH) are sent out by at
least one radio access device (NB, AP) of the radio
communication system.
11. A radio communication system having at least one radio
access device (NB, AP) comprising at least one transmitting
device (SE) for sending out signals of at least one

country-specific pilot channel (C-CPC) with information (info)
on at least one operator (OP1, 0P2) of a radio communication
system, of at least one operator-specific pilot channel
(OP1-CPC) with information (info) on at least one radio
communication system (RAT1, UMTS, WLAN) and of at least one
system-specific pilot channel (RAT1-BCH).
12. A user terminal (UE) having at least
- one receiving device (EE) for receiving at least one country-
specific pilot channel (C-CPC), one operator-specific pilot
channel (OP1-CPC) and one system-specific pilot channel
(RAT1-BCH),
- one evaluating device (AW) for evaluating information (info)
of the received at least one country-specific pilot channel
(C-CPC) with respect to at least one operator (OP1, OP2, ...,
OPn) and for selecting an operator (OP1), for evaluating
information (info) of the received operator-specific pilot
channel (OP1-CPC) of the selected operator (OP1) and for
selecting a radio communication system (RAT1, UMTS) and for
evaluating information of the received system-specific pilot
channel (RAT1-BCH) of the selected radio communication system
(RAT1, UMTS) and for deciding on an access to the selected
radio communication system (RAT1, UMTS), and
- one transmitting device (SE) for sending out signals for an
access to the selected radio communication system (RAT1, UMTS).

The invention relates to a method for establishment of a
connection in a radio communication system, wherein a user
terminal (UE) selects an operator (OPI), based on
information (info) on at least one operator (OPI,OP2) of a radio
communication system in a country-specific pilot channel (C-CPC),
selects a radio communication system (RATI,IMTS) based on
information (info) on at least one radio communication
system in an operator-secific pilot channel (OPI-CPC) for the selected operator (OPI) and carries out an access to the
selected radio communication system (RATI,UMTS) for establishment
of a connection.

Documents:

02496-kolnp-2008-abstract.pdf

02496-kolnp-2008-claims.pdf

02496-kolnp-2008-correspondence others.pdf

02496-kolnp-2008-description complete.pdf

02496-kolnp-2008-drawings.pdf

02496-kolnp-2008-form 1.pdf

02496-kolnp-2008-form 2.pdf

02496-kolnp-2008-form 3.pdf

02496-kolnp-2008-form 5.pdf

02496-kolnp-2008-gpa.pdf

02496-kolnp-2008-international publication.pdf

02496-kolnp-2008-international search report.pdf

02496-kolnp-2008-pct request form.pdf

2496-KOLNP-2008-(19-03-2014)-CLAIMS.pdf

2496-KOLNP-2008-(19-03-2014)-CORRESPONDENCE.pdf

2496-KOLNP-2008-(19-03-2014)-DESCRIPTION (COMPLETE).pdf

2496-KOLNP-2008-(19-03-2014)-DRAWINGS.pdf

2496-KOLNP-2008-(19-03-2014)-FORM-1.pdf

2496-KOLNP-2008-(19-03-2014)-FORM-13.pdf

2496-KOLNP-2008-(19-03-2014)-FORM-2.pdf

2496-KOLNP-2008-(19-03-2014)-OTHERS.pdf

2496-KOLNP-2008-(19-03-2014)-PETITION UNDER RULE 137.pdf

2496-KOLNP-2008-(27-03-2014)-CORRESPONDENCE.pdf

2496-KOLNP-2008-(27-03-2014)-OTHERS.pdf

2496-KOLNP-2008-(30-05-2013)-ABSTRACT.pdf

2496-KOLNP-2008-(30-05-2013)-CLAIMS.pdf

2496-KOLNP-2008-(30-05-2013)-CORRESPONDENCE.pdf

2496-KOLNP-2008-(30-05-2013)-DESCRIPTION (COMPLETE).pdf

2496-KOLNP-2008-(30-05-2013)-DRAWINGS.pdf

2496-KOLNP-2008-(30-05-2013)-FORM-1.pdf

2496-KOLNP-2008-(30-05-2013)-FORM-2.pdf

2496-KOLNP-2008-(30-05-2013)-FORM-3.pdf

2496-KOLNP-2008-(30-05-2013)-FORM-5.pdf

2496-KOLNP-2008-(30-05-2013)-PA.pdf

2496-KOLNP-2008-(30-05-2013)-PETITION UNDER RULE 137.pdf

2496-KOLNP-2008-CORRESPONDENCE OTHERS 1.2.pdf

2496-KOLNP-2008-CORRESPONDENCE OTHERS-1.1.pdf

2496-KOLNP-2008-CORRESPONDENCE OTHERS-1.3.pdf

2496-KOLNP-2008-FORM 18.pdf

2496-KOLNP-2008-INTERNATIONAL EXM REPORT.pdf

2496-KOLNP-2008-OTHERS.pdf

2496-KOLNP-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

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Patent Number

264112

Indian Patent Application Number

2496/KOLNP/2008

PG Journal Number

50/2014

Publication Date

12-Dec-2014

Grant Date

08-Dec-2014

Date of Filing

19-Jun-2008

Name of Patentee

NOKIA SIEMENS NETWORKS GMBH & CO.KG.

Applicant Address

ST. MARTIN STR. 76, 81541 MUNCHEN

Inventors:

#	Inventor's Name	Inventor's Address
1	PETER SLANINA	WEHRGASSE 13, 3441 JUDENAU
2	JIJUN LUO	SACHRANGER STRASSE 2, 81549 MUNCHEN 13
3	JIANMING PAN	BERGENG 5/1/6 1220 WIEN
4	EIMAN BUSHRA MOHYELDIN	FORSTENRIEDER ALLEE 202, 81476 MUNCHEN

PCT International Classification Number

H04Q 7/38

PCT International Application Number

PCT/EP2006/069641

PCT International Filing date

2006-12-13

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	EP05027892	2005-12-20	EUROPEAN UNION