Title of Invention	METHOD AND APPARATUS FOR DETERMIMG FREQUENCY PLANNING MEASUREMENT DATA IN A CELLULAR COMMUNICATIONS SYSTEM.
Abstract	A method and apparatus for determining frequency planting measrement data in a celluer commonication sys- tem (1) comprising allcating neighbour XXX (208, 210, 212) to provide measurment data for frequency planting wherein the neighbour lists (208, 210, 212) are allocated on a per calf basisi. Thus different lists (208, 210, 212) may be allocated by the same base station (28) to different mobile stadons (44, 46, 68) for respective calls (204) that overlap in time. A different neighbour list (208, 210, 21) may be allocated for substantially each call (204) conducted by a base station (28) of the celluer communication system (1) composed to respective directly proceding calls or may be alloacted for substntially each of predetermined number of calls conducted by a base station (28) of the celluer communication system (1) comapred to the predetermined number of directly preceding cells. At least substentially all test frequency (206) for the all (16) served by the base station (28) may thereby be coverd over a phurality of calls (204).

Title of Invention

METHOD AND APPARATUS FOR DETERMIMG FREQUENCY PLANNING MEASUREMENT DATA IN A CELLULAR COMMUNICATIONS SYSTEM.

Abstract

A method and apparatus for determining frequency planting measrement data in a celluer commonication sys- tem (1) comprising allcating neighbour XXX (208, 210, 212) to provide measurment data for frequency planting wherein the neighbour lists (208, 210, 212) are allocated on a per calf basisi. Thus different lists (208, 210, 212) may be allocated by the same base station (28) to different mobile stadons (44, 46, 68) for respective calls (204) that overlap in time. A different neighbour list (208, 210, 21) may be allocated for substantially each call (204) conducted by a base station (28) of the celluer communication system (1) composed to respective directly proceding calls or may be alloacted for substntially each of predetermined number of calls conducted by a base station (28) of the celluer communication system (1) comapred to the predetermined number of directly preceding cells. At least substentially all test frequency (206) for the all (16) served by the base station (28) may thereby be coverd over a phurality of calls (204).

Full Text	METHOD AND APPARATUS FOR FRSQUENCY PLANNING IN A CELLULAR COMMUNICATIONS SYSTEM USING MODIFIED NEIGHBOUR LISTS Field of the Invention The present invention relates to cellular communication systems. The present invention relates in particular, but not exclusively, to data collection for frequency planning for cellular communication systems based on measurement reports. Cellular communications systems to which the present invention may be applied include for example, Global System for Mobile Telecommunication (GSM), Universal Mobile Telecommunications System (UMTS), and General Packet Radio Service (GPRS) systems. Background of the Invention In a cellular communications system, the area over which service is provided is divided into a number of smaller areas called cells. Typically each. cell is served from, a base Transceiver station (BTS) which has an antenra or antennas for transmission to and reception from a large number of user stations, normally mobile stations e.g. mobile telephones. Examples of established harmonised, cellular radio communications systems are Global System for Mobile Telecommunication (GSM) and General Packet Radio Service (GPRS) systems. A further harmonised standard being introduced is the Universal Mobile Telecommunications System (UMTS). WO 2004/066655 PCT/EP2004/050036 -2- In cellular communication systems, multiple frequency channels are used in each cell, as well as used in different cells. A technique known as frequency hopping is used within cells to provide diversity. The choice of which frequencies are to be used in which cells plays an important rate in the efficiency and quality of service in. a system. For example, adjoining cells are prone to interfere with each other, so appropriate selection of frequencies may reduce such interference. However, in order to achieve efficient usage of resources and provide service to large numbers of users, practically it is necessary to employ frequency plans that may involve potential interference. Various methods are known for testing systems to acquire, data to enable frequency plans to be improved. One example is drive testing. Another example is to collect data from measurement reports that are anyway produced in the operation of the cellular communication system. Such measurement reports are produced by mobile stations and transmitted to control unite of the system infrastructure. The measurement reports comprise details of e.g. signal strength measured by the mobile station on the frequency or frequencies it is communicating with in its own cell, In addition, the measurement reports comprise similar details of frequencies that correspond to certain neighbouring cells, The mobile station is informed of which frequencies (and in effect which neighbouring cells) to mueasure and report by virtue of these being on a so called neighbour list, determined by a control unit of the infrastrtucture of the system and communicated to the user station. The neighbour list is primary provided WO 2004/066655 PCT/EP2004/050036 -3- to enable preparation for handover however of interest here is the fact that measurements of the neighbouring cells and frequencies can be used in frequency planning In GSM systems, the neighbour list is transmitted to the mobile stations on a control channel called the Slow Aasociated Control Channel (SACCH), and hence the neighbour list may conveniently be called a SACCH neighbour list Neighbours included for the primary purpose of potential handover planning me known as configured neighbours. For the purpose of providing measurement repents for collecting data for frequency planning, extra measurement frequencies are added ta the SACCCH neighbour list. The extra frequencies are known as test fcequencies or test neghbours. Convertionally the same SACCH neighbour list is transmitted to all user stations in a given cell. Also, conventionally the tats frequencies employed in a given cell are changed once a day, so that over the course of a number of days all the frequencies it is desired to test may be included. In each system there is a predetermined limit as to the total number of neighbour cells/frequenries that may be set. In GSM this limit is 32. However, there may be a large number of configured netghbours in a given cell leaving only a small number of test frequencies that may be employed each day. Thus the conventional approach is often slow and inefficient. WO 2004/066655 PCT/EP2004/050036 -4- Moreover, by requiring different best frequencies to be tested on different days, the resulting data may not be properly representative of the real life situation, as statistical affects due to different communications traffic on different days may distort the results. Summary of the Invention In a first aspect, the present invention provides a method of determining frequency planning measurement data in a cellular communications system, as daimed in claim 1. In a futther aspect the present invention provides a method of frequency planning in a cellular communications system, as ctaimed in claim 7. In A further aspect, the present invention, provides a storage medium storing processor impleinentable instructions , as claimed in claim 8. In a further aspert the present invention piovides apparatus for determining frequency planning measurement data in a cellular communications system, as claimed, in claim 9. In a further aspect, the present invention provides apparatus for frequency planning in a cellufar communications system, at claimed in claim 15. WO 2004/066655 PCT/EP2004/050036 -5- The present invention tends to improve the quality of the data collected, by recording data for more frequencies over a shorter time period. Brief Description of the Drawings Embodiments of the priesent invention will now be described, by way of example only, with reference to the accompanying drawings in which FIG. 1is a schematic illustration of a small part of a GSM cellular communication system; FIG. 2 shows a table of frequency channels allocated against neighbour positions over the cours of three calls and FIG.3 is a table showing which of the frequency channels shown in FIG. 2 will have been measured during the calls shown in FIG. 2. Description of00Preferred Embodiment FIG-1 is schematic illustration of a small part of a GSM cellular communication system 1 having a coverage area formed by a number of cells 12- 22. A conventional schematic representation showing a hexagonal cell pattern has been used to depict the cell areas but in practic the shape and size of each cell will be different. WO 2004/066655 PCT/EP2004/050036 -6- In each cell there is a base station system (BSS) 24-34. In this embodiment each BSS 24-34 is an integrated base station controller (BSC) and base transceiver station (BTS). In practice large numbers of mobile stations (MSs) will receive service from the infrastructure shown In FIG. 1. However, for clarity, only a few such. MSs are shown namely MSs 42, 44, 46 and 48. The BSSs 144-34 are each coupled to a mobile Service Switing Centre (MSC) 50. The MSC 50 is coupled to an Operations and Management Centre (OMC) 49 and to a Public Swithed Telephone Network (PSTN) 51. In operation, the BSSs 24-34 raceived radio signals from the MSs and transmits radio signals to the MSs. The MSC 50 provides interconnectton and routing both within the cellular communication system 10 (in co-operation with others MSCs, not shown, covering other areas) and to external element via the PSTN51. The OMC 49 is usedty the operator of the cellular communicationm system 1 to configure and maintain the system 1. Each BSS 24-34 allocates and transmits neighbour lists to MSs receiving service In the corresponding cells. This is implemented by databases and software at the respective BSSs, under instruction from the OMC 49. The neighbour lis is are transmitted from the BSSs to the MSs using the Slow Associated Control Channel(SACCH). WO 2004/066655 PCT/EP2004/050036 -7- In this embodiment, the BSSs 24-34 have been adapted to offer, and provide for, a different way of Conning the SACCH neighbour lists, as will be described in more detail below. However, this adaptation may be implemented in any suitable manner. A new module may be added to a conventional BSS, The module may consist of a single discrete entity added, to a conventional BSS, or may alternatively be formed by adapting existing parts of a conventional BSS, far example by repiogiamming of a one or more processors therein. As such the required adaptation may be implemented the form of processor-implementable instructions stored on a storage medium such as a floppy disk, hard disk; PROM, RAM or any combination of these or other storage media. Furthermore, whether a separate entity or an adaptation of existing parts or a combination of these, the module may be implemented in the form of hardware, firmware, software, ot any combination of these. It is also within the contemplation of the invention that such adaptation of the means for forming SACCH neighbour lists may alternatively be controlled implemented in full, or implemented in part, by a module added to or formed by adaptation of any other suitable part of the cellular communication system 1 or other cellular communication systems. For example this may be implemented instead at separate. BTSs or BSCs when the BSSs are of a form comprising separate BTSs and BSCs. As another example, this may be implemented at OMCs, in situation where OMCs of systems can directly implement neighbout lists. Further, in the case of other system infrastructures or layouts, WO 2004/066655 PCT/EP2004/050036 -8- impplementation may be at any appropriate system node such as any other appropriate type of base station, base station controller etc Alternatively various parts of the process and means for forming the adapted! neighbour lists can be carrried out by various componenis distributed at different locations or entitles within the above described cellular communication system 1 or any other suitable cellular communication network or system. The way in which, in this embodiment, the BSSs 24-34 form the SACCH neighbour lists will now be described, with reference to FIG, 2 and 3. In. this embodiment , the BSSs 24-34 each form and allocate SACCH neighbour listes on a per call basis. Thus, in terms of an overview, the SACCH neighbour listes fromed and allocated separately east time a call is conducted to/from each MS. In this embodiment, a different SACCH neighbour list is formed for each call in each cell. This process will now be described by use of a simplified example. FIG, 2 shows a table of frequency channels 206 allocated against neighbour positions 202 over the course of three calls 204 (call number 1,2 and 3 in the table) serviced BSS 28 with respect to MSs in its cell, i.e., a first call oanducted. by/for MS 44 a second call conducted by/for MS 46, and a third call conducted by/for MS 48.In this example these calls are taking place at the same time (i.e. overlap in time, although not necessarily starting of ending at the same time), although the process described-below may also be applied to different calls at different times. WO 2004/066655 PCT/EP2004/050036 -9- In this simplified example, for the sake of clarity, only 12 neighbour positions 202, numbered 1-12 are included. However, as mentioned earlier, under GSM a maximum of 32 are usually employed. Thus, in this example in any neighbour list only twelve frequencies (i e. frequency channels) may be included Also, for the sake of carity, the number of available frequencies (frequency channels) is limited rn this simplified example to sixteen, made up of the eight frequencies called 1-3 in FIG. 2 and the eight frequencies called 12-19 in FIG. 2, In this example, the frequencies 1-6 and 12-19 are used to indicate how there are usually gaps in the frequency channels employed, e.g. here frequencies 9-11 are unavailable. In this example, for the first call, the BSS 28 forms, allocates and transmits (to the MS 44 conducyting the first call) a first neighbour list 208. The first neighbour list 208 comprises configured frequencies 1, 3,4,7,12 and 17 in neighbour positions 1 to 6 respectively. (Stricly speaking these are the Broadcast/ Control Channel (BCCH) parts of the frequency entries in the neighbour list; which in full also include Base Transceiver Station Identity Code (BSIC) parts. However, snch details aie well known to the skilled person in the art of cellular communications systems, in particular GSM, and need not be described further here for the purpose of explaining the present invention,) The first neighbour list 208 further comprises test frequencies 2, 5, 6,8,13 and 14 in neighbour positions 7 to 12 respectively. WO 2004/066655 PCT/EP2004/050036 -10- For the second call, the ESS 28 forms, allocates and transmits (to the MS 46 conducting the second call) a second neighbour list 210, The second neighbour list 210 comprises configured frequencies 1-4,3-5,4 -7,7-4,12-4 and 17-3 in neighbour positions 1 to 6 respectively- These are the same configured frequencies/neighbour positions as in the first neighbour list 208. However, the second neighbour list 210 further comprises test fnequeaties 15,16,16,19, 2 and 5 in neighbour positions 7 to 12 respectively i e. overall the second neighbour list 210 is different (o the first neighbour list 209, For the third call, the BSS 28 forms, allocates and transmits (to the MS 48 conducting the third call) a third neighbour list 212. The third neighbour list 212 conpsprises configured frequencies 1-4, 3-5, 4-7, 7-4, 12- 4 and 17-3 in neighbour positions 1 to 6 respectively . These are the same configured frequences/neighbour position as in the first neightour list 208 and the second frequencies 6,8,13,14,15 and 16 in neighbour positions 7 to 12 respectively i.e. overall the third neighbour list 217 is different to both the first neighbour list 208 and the second neighbour list 210. Thus, for each of the three calls, a different neighbour list is employed. A benefit of the frequency allocation described above wite reference to FIG. 2 may be seen with reference to FIG.3 . FIG. 3 is a table showing which of the above described frequencies 206 will have been measured during the above described calls 204 (this is indicated in FIG. 3 by an "X" in. esch case). As can be WO 2004/066655 PCT/EP2004/050036 -11- seen, all 16 frequencies (i.e. l-8 and 12-19) will have been measured. This is in contrast to the fact that if the same neighbour list has been used for all three calls (as per the prior art) only some the fiequencies would have been measured, (Of course, in some applications, not all frequencies will be measure, however there will still tend to be an advantageous increase in the number of frequencies measured compared to the number measured with a common unchanging neighbour list.) In the above described embodiment a different SACCH neighbour list is formed for each call in each cell. However, there are a number of ways in which a less extreme variation is employed, whilst still making effective use of the concept of forming and allocating the SACCH neighbour list on a per call basis. For example it may be that all possible combinations are testad in a given time before it is wished to stop testing. In this case some or all of the transmitted combinations may be used again. As another example, a subset of combinations of neighbour lists may be provided which are belleved to cover all variables requised to be assessed, and these may be opened on a cyclical basis. As another example, the process may be applied to substantially all calls, but not absohuly all calls, Calls may be omitted from variation of neighbour list for any one or any combination of reasons, for example obtain calls may be excluded due to processing limitations, random, errors, requirement to provide a WO 2004/066655 PCT/EP2004/050036 -12- constant neighbout list for some other reasom and so on . Another possibility is, calls to certain MSs may be excluded from variation. AS another example, the process may be applied to some but not all the cells of the cellular communications system. As another example, the process may be applied for some period or periods during the day but not all day. As another example, the neighbour list may be varied for plural numbers of calls rather than every call. For example, a given neighbour list may be used for two calls. then changed to a new list used for a further two calls, and so an. Any appropriate number of calls for such a regime (i.e. as opposed, to every one or every two calls) may be used according to the requirements at the particular system of situation under consideration, Also any two or more of the above examples may occur in combination. Thus, the terminology "on a per call basis " as used herein is to be understood as encompassing different ways of varying the neighbour lists according to different calls bening serviced, rather than being in.dependent.of calls, and rather than being uniformly implemented icrespective of which calls are being processed. WO 2004/066655 PCT/EP2004/050036 -13- Although the above embodiment has been described in terms of a GSM system, it will be appreciated that the present invention may be embodied in any suitable cellular communications system in which neighbour position, or equivalen characteristics, may be used to provide measurement data for frequency planning. The present invention may in appropriate discumstances provide, inter alia, one more of the following advantages. the data collection.time required to provide a given amount of useful input for frequency planning is reduced; the total amount of data required to be collected to provide a given amount pf useful input for frequency planning is reduced; reduced data analysis time; reduce hardware and software requirements process data due to less data; reduction in cycle time required to provide a given amount of useful input for frequency planning, thereby providing more representative frequency data corresponding more closely to actual cell traffic. WO 2004/066655 PCT/EP2004/050036 -14- CLAIMS 1. A method of determining frequency planning measurement data in a cellular communications system (1), comprising. allocating neighbour lists (208, 210, 212) to provide measurement date for frequency planning; wherein the neighbour lists (208,210,212) are allocated on a per call basis. 2. A method according to claim 1, wherein different neighbour lists (208, 210 212) are alloocated by the same base station (28) to different mobile stations (44, 46,48) for respective calls (204) that overlap in time. 3. A method according to claim 1 or 2, wherein 9 different neighbour list (308,210, 212) is allocated for at least substantially each call (204) conducted by a base station (28) of the cellular communicational system (1) compared to respect directly preceding calls. 4. A method according to claim 1 or 2, wherein a different neighbour list (208,, 210 212) is allocated for at least substantially each of a prede termined number of calls conducted by a base station (28) of the cellular communication system (1), compared for the predetennined numtaer of directly pteoeding calls. 5. A method according to any of claims 1 to 4 wherein the neighbour lists (208, 2l0, 212,) are allocated on a per call basis such as to cover over a plurality of WO 2004/066655 PCT/EP2004/050036 -15- calls (204), at least substantially all test frequencies (206) for the cell (16) served by the base station (28). 6. A method according to claim 5, further comprising repeating, on a cyclical basic comprising repeated pluralities of calls the neghbour lisis (208,210,212) allocated on a per call basis covering at least substantially all the test frequencies (206). 7. A method of frequency planning in a cellular communications system, comprising using frequency planning measurement data acquired by a process comprising the method according to any of claims 1 to 6. 8. A storage medium storing processor implementable instruction for controlling one or more processors to carry out the method of any of claims 1 to 7. 9. Apparatus for determining frequency planning measurement data in a cellular communications system (1), comprising. means for allocating neghbour lists to provide measurement data for frequency planning wherein the means for allocating neighbour lists are adapted to allocate the neighbour lists (208,210,212) on a per call basis. 10. Apparatus according to claim 10 wherein the means for allocating neighbour lists are adapted to allocate different neighbour lists (208, 210,212) WO 2004/066655 PCT/EP2004/050036 -16- from the same base station (28) to different mobile stations (44,46,48) for respective calls (203) that overlap in time, 11. Apparatus according to claim 9 or 10 wherein the means for allocating neighbour lists are adepted to alloocate a different neighbour list (208, 210, 212) for at least substantially each call (204) conducted by a base station (28) of the cellular communication system (1), compared to respective directly preceding, calls. 12. Apparatus according to claim 9 or 10 wherein the. means for allocating neighbour lists are adapted to allocate a different neighbour list (208, 210,, 212) for at least substantiaally each of a predetermined number of calls conducted by a base station (28) of the cellular communications system (1 ), compared to the predetermined number of directly preceding calls. 13. Apparatus according to any of claims 9 to 12 wherein the means for allocating neighbour lists are adapted to allocate the neighbour lists (208, 210, 212) on a per call basis such as to cover, over a plurality of calls (204), at least substantially all test frequencies (206) for the cell (16) served by the base station (28). 14. Apparatus according to claim 13, the means for allocating neighbour lists are adapted to repeat on a cyclical basis comprising repeated pluralities of calls, the neighbom lists (208,210,212) allocated on a per call basis covering at least substantially all the test frequencies (206). WO 2004/066655 PCT/EP2004/050036 -17- 15. Apparatus for frequency planning in a cellular communications system, comprising means adapted to use frequency planning the measurement data acquired by apparatus comprising appatous according to any of claim 9 to 14. 16. A method of determining frequency planning measurement data in a cellular communication system substantially as hereinbefore described with reference to the accompanying drawings, 17. Apparatus for determining frequency planning measurement data in a cellular communications system substantially as hereinbefore described, with reference to the accompanying drawings. A method and apparatus for determining frequency planting measrement data in a celluer commonication sys- tem (1) comprising allcating neighbour XXX (208, 210, 212) to provide measurment data for frequency planting wherein the neighbour lists (208, 210, 212) are allocated on a per calf basisi. Thus different lists (208, 210, 212) may be allocated by the same base station (28) to different mobile stadons (44, 46, 68) for respective calls (204) that overlap in time. A different neighbour list (208, 210, 21) may be allocated for substantially each call (204) conducted by a base station (28) of the celluer communication system (1) composed to respective directly proceding calls or may be alloacted for substntially each of predetermined number of calls conducted by a base station (28) of the celluer communication system (1) comapred to the predetermined number of directly preceding cells. At least substentially all test frequency (206) for the all (16) served by the base station (28) may thereby be coverd over a phurality of calls (204).

Full Text

METHOD AND APPARATUS FOR FRSQUENCY PLANNING IN A CELLULAR COMMUNICATIONS SYSTEM
USING MODIFIED NEIGHBOUR LISTS
Field of the Invention
The present invention relates to cellular communication systems. The
present invention relates in particular, but not exclusively, to data collection for
frequency planning for cellular communication systems based on measurement
reports. Cellular communications systems to which the present invention may be
applied include for example, Global System for Mobile Telecommunication
(GSM), Universal Mobile Telecommunications System (UMTS), and General
Packet Radio Service (GPRS) systems.
Background of the Invention
In a cellular communications system, the area over which service is
provided is divided into a number of smaller areas called cells. Typically each.
cell is served from, a base Transceiver station (BTS) which has an antenra or
antennas for transmission to and reception from a large number of user stations,
normally mobile stations e.g. mobile telephones. Examples of established
harmonised, cellular radio communications systems are Global System for Mobile
Telecommunication (GSM) and General Packet Radio Service (GPRS) systems. A
further harmonised standard being introduced is the Universal Mobile
Telecommunications System (UMTS).

WO 2004/066655 PCT/EP2004/050036
-2-
In cellular communication systems, multiple frequency channels are used
in each cell, as well as used in different cells. A technique known as frequency
hopping is used within cells to provide diversity. The choice of which
frequencies are to be used in which cells plays an important rate in the efficiency
and quality of service in. a system. For example, adjoining cells are prone to
interfere with each other, so appropriate selection of frequencies may reduce
such interference.
However, in order to achieve efficient usage of resources and provide
service to large numbers of users, practically it is necessary to employ frequency
plans that may involve potential interference. Various methods are known for
testing systems to acquire, data to enable frequency plans to be improved. One
example is drive testing. Another example is to collect data from measurement
reports that are anyway produced in the operation of the cellular communication
system. Such measurement reports are produced by mobile stations and
transmitted to control unite of the system infrastructure.
The measurement reports comprise details of e.g. signal strength
measured by the mobile station on the frequency or frequencies it is
communicating with in its own cell, In addition, the measurement reports
comprise similar details of frequencies that correspond to certain neighbouring
cells, The mobile station is informed of which frequencies (and in effect which
neighbouring cells) to mueasure and report by virtue of these being on a so called
neighbour list, determined by a control unit of the infrastrtucture of the system
and communicated to the user station. The neighbour list is primary provided

WO 2004/066655 PCT/EP2004/050036
-3-
to enable preparation for handover however of interest here is the fact that
measurements of the neighbouring cells and frequencies can be used in
frequency planning
In GSM systems, the neighbour list is transmitted to the mobile stations on
a control channel called the Slow Aasociated Control Channel (SACCH), and
hence the neighbour list may conveniently be called a SACCH neighbour list
Neighbours included for the primary purpose of potential handover planning
me known as configured neighbours. For the purpose of providing measurement
repents for collecting data for frequency planning, extra measurement
frequencies are added ta the SACCCH neighbour list. The extra frequencies are
known as test fcequencies or test neghbours.
Convertionally the same SACCH neighbour list is transmitted to all user
stations in a given cell. Also, conventionally the tats frequencies employed in a
given cell are changed once a day, so that over the course of a number of days all
the frequencies it is desired to test may be included.
In each system there is a predetermined limit as to the total number of
neighbour cells/frequenries that may be set. In GSM this limit is 32. However,
there may be a large number of configured netghbours in a given cell leaving
only a small number of test frequencies that may be employed each day. Thus
the conventional approach is often slow and inefficient.

WO 2004/066655 PCT/EP2004/050036
-4-
Moreover, by requiring different best frequencies to be tested on different
days, the resulting data may not be properly representative of the real life
situation, as statistical affects due to different communications traffic on different
days may distort the results.
Summary of the Invention
In a first aspect, the present invention provides a method of determining
frequency planning measurement data in a cellular communications system, as
daimed in claim 1.
In a futther aspect the present invention provides a method of frequency
planning in a cellular communications system, as ctaimed in claim 7.
In A further aspect, the present invention, provides a storage medium
storing processor impleinentable instructions , as claimed in claim 8.
In a further aspert the present invention piovides apparatus for
determining frequency planning measurement data in a cellular communications
system, as claimed, in claim 9.
In a further aspect, the present invention provides apparatus for
frequency planning in a cellufar communications system, at claimed in claim 15.

WO 2004/066655 PCT/EP2004/050036
-5-
The present invention tends to improve the quality of the data collected,
by recording data for more frequencies over a shorter time period.
Brief Description of the Drawings
Embodiments of the priesent invention will now be described, by way of
example only, with reference to the accompanying drawings in which
FIG. 1is a schematic illustration of a small part of a GSM cellular
communication system;
FIG. 2 shows a table of frequency channels allocated against neighbour
positions over the cours of three calls and
FIG.3 is a table showing which of the frequency channels shown in FIG. 2
will have been measured during the calls shown in FIG. 2.
Description of00Preferred Embodiment
FIG-1 is schematic illustration of a small part of a GSM cellular
communication system 1 having a coverage area formed by a number of cells 12-
22. A conventional schematic representation showing a hexagonal cell pattern
has been used to depict the cell areas but in practic the shape and size of each
cell will be different.

WO 2004/066655 PCT/EP2004/050036
-6-
In each cell there is a base station system (BSS) 24-34. In this embodiment
each BSS 24-34 is an integrated base station controller (BSC) and base transceiver
station (BTS). In practice large numbers of mobile stations (MSs) will receive
service from the infrastructure shown In FIG. 1. However, for clarity, only a few
such. MSs are shown namely MSs 42, 44, 46 and 48.
The BSSs 144-34 are each coupled to a mobile Service Switing Centre
(MSC) 50. The MSC 50 is coupled to an Operations and Management Centre
(OMC) 49 and to a Public Swithed Telephone Network (PSTN) 51.
In operation, the BSSs 24-34 raceived radio signals from the MSs and
transmits radio signals to the MSs. The MSC 50 provides interconnectton and
routing both within the cellular communication system 10 (in co-operation with
others MSCs, not shown, covering other areas) and to external element via the
PSTN51. The OMC 49 is usedty the operator of the cellular communicationm
system 1 to configure and maintain the system 1.
Each BSS 24-34 allocates and transmits neighbour lists to MSs receiving
service In the corresponding cells. This is implemented by databases and software
at the respective BSSs, under instruction from the OMC 49. The neighbour lis is
are transmitted from the BSSs to the MSs using the Slow Associated Control
Channel(SACCH).

WO 2004/066655 PCT/EP2004/050036
-7-
In this embodiment, the BSSs 24-34 have been adapted to offer, and
provide for, a different way of Conning the SACCH neighbour lists, as will be
described in more detail below.
However, this adaptation may be implemented in any suitable manner. A
new module may be added to a conventional BSS, The module may consist of a
single discrete entity added, to a conventional BSS, or may alternatively be
formed by adapting existing parts of a conventional BSS, far example by
repiogiamming of a one or more processors therein. As such the required
adaptation may be implemented the form of processor-implementable
instructions stored on a storage medium such as a floppy disk, hard disk;
PROM, RAM or any combination of these or other storage media. Furthermore,
whether a separate entity or an adaptation of existing parts or a combination of
these, the module may be implemented in the form of hardware, firmware,
software, ot any combination of these.
It is also within the contemplation of the invention that such adaptation of
the means for forming SACCH neighbour lists may alternatively be controlled
implemented in full, or implemented in part, by a module added to or formed by
adaptation of any other suitable part of the cellular communication system 1 or
other cellular communication systems. For example this may be implemented
instead at separate. BTSs or BSCs when the BSSs are of a form comprising
separate BTSs and BSCs. As another example, this may be implemented at
OMCs, in situation where OMCs of systems can directly implement neighbout
lists. Further, in the case of other system infrastructures or layouts,

WO 2004/066655 PCT/EP2004/050036
-8-
impplementation may be at any appropriate system node such as any other
appropriate type of base station, base station controller etc Alternatively various
parts of the process and means for forming the adapted! neighbour lists can be
carrried out by various componenis distributed at different locations or entitles
within the above described cellular communication system 1 or any other
suitable cellular communication network or system.
The way in which, in this embodiment, the BSSs 24-34 form the SACCH
neighbour lists will now be described, with reference to FIG, 2 and 3.
In. this embodiment , the BSSs 24-34 each form and allocate SACCH
neighbour listes on a per call basis. Thus, in terms of an overview, the SACCH
neighbour listes fromed and allocated separately east time a call is conducted
to/from each MS. In this embodiment, a different SACCH neighbour list is
formed for each call in each cell.
This process will now be described by use of a simplified example. FIG, 2
shows a table of frequency channels 206 allocated against neighbour positions
202 over the course of three calls 204 (call number 1,2 and 3 in the table)
serviced BSS 28 with respect to MSs in its cell, i.e., a first call oanducted. by/for
MS 44 a second call conducted by/for MS 46, and a third call conducted by/for
MS 48.In this example these calls are taking place at the same time (i.e. overlap
in time, although not necessarily starting of ending at the same time), although
the process described-below may also be applied to different calls at different
times.

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In this simplified example, for the sake of clarity, only 12 neighbour
positions 202, numbered 1-12 are included. However, as mentioned earlier,
under GSM a maximum of 32 are usually employed. Thus, in this example in
any neighbour list only twelve frequencies (i e. frequency channels) may be
included Also, for the sake of carity, the number of available frequencies
(frequency channels) is limited rn this simplified example to sixteen, made up of
the eight frequencies called 1-3 in FIG. 2 and the eight frequencies called 12-19 in
FIG. 2, In this example, the frequencies 1-6 and 12-19 are used to indicate how
there are usually gaps in the frequency channels employed, e.g. here frequencies
9-11 are unavailable.
In this example, for the first call, the BSS 28 forms, allocates and transmits
(to the MS 44 conducyting the first call) a first neighbour list 208. The first
neighbour list 208 comprises configured frequencies 1, 3,4,7,12 and 17 in
neighbour positions 1 to 6 respectively. (Stricly speaking these are the Broadcast/
Control Channel (BCCH) parts of the frequency entries in the neighbour list;
which in full also include Base Transceiver Station Identity Code (BSIC) parts.
However, snch details aie well known to the skilled person in the art of cellular
communications systems, in particular GSM, and need not be described further
here for the purpose of explaining the present invention,) The first neighbour list
208 further comprises test frequencies 2, 5, 6,8,13 and 14 in neighbour positions
7 to 12 respectively.

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For the second call, the ESS 28 forms, allocates and transmits (to the MS 46
conducting the second call) a second neighbour list 210, The second neighbour
list 210 comprises configured frequencies 1-4,3-5,4 -7,7-4,12-4 and 17-3 in
neighbour positions 1 to 6 respectively- These are the same configured
frequencies/neighbour positions as in the first neighbour list 208. However, the
second neighbour list 210 further comprises test fnequeaties 15,16,16,19, 2 and 5
in neighbour positions 7 to 12 respectively i e. overall the second neighbour list
210 is different (o the first neighbour list 209,
For the third call, the BSS 28 forms, allocates and transmits (to the MS 48
conducting the third call) a third neighbour list 212. The third neighbour list 212
conpsprises configured frequencies 1-4, 3-5, 4-7, 7-4, 12- 4 and 17-3 in neighbour
positions 1 to 6 respectively . These are the same configured
frequences/neighbour position as in the first neightour list 208 and the second
frequencies 6,8,13,14,15 and 16 in neighbour positions 7 to 12 respectively i.e.
overall the third neighbour list 217 is different to both the first neighbour list 208
and the second neighbour list 210.
Thus, for each of the three calls, a different neighbour list is employed.
A benefit of the frequency allocation described above wite reference to
FIG. 2 may be seen with reference to FIG.3 . FIG. 3 is a table showing which of
the above described frequencies 206 will have been measured during the above
described calls 204 (this is indicated in FIG. 3 by an "X" in. esch case). As can be

WO 2004/066655 PCT/EP2004/050036
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seen, all 16 frequencies (i.e. l-8 and 12-19) will have been measured. This is in
contrast to the fact that if the same neighbour list has been used for all three calls
(as per the prior art) only some the fiequencies would have been measured,
(Of course, in some applications, not all frequencies will be measure, however
there will still tend to be an advantageous increase in the number of frequencies
measured compared to the number measured with a common unchanging
neighbour list.)
In the above described embodiment a different SACCH neighbour list is
formed for each call in each cell. However, there are a number of ways in which a
less extreme variation is employed, whilst still making effective use of the
concept of forming and allocating the SACCH neighbour list on a per call basis.
For example it may be that all possible combinations are testad in a given
time before it is wished to stop testing. In this case some or all of the transmitted
combinations may be used again.
As another example, a subset of combinations of neighbour lists may be
provided which are belleved to cover all variables requised to be assessed, and
these may be opened on a cyclical basis.
As another example, the process may be applied to substantially all calls,
but not absohuly all calls, Calls may be omitted from variation of neighbour list
for any one or any combination of reasons, for example obtain calls may be
excluded due to processing limitations, random, errors, requirement to provide a

WO 2004/066655 PCT/EP2004/050036
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constant neighbout list for some other reasom and so on . Another possibility is,
calls to certain MSs may be excluded from variation.
AS another example, the process may be applied to some but not all the
cells of the cellular communications system.
As another example, the process may be applied for some period or
periods during the day but not all day.
As another example, the neighbour list may be varied for plural numbers
of calls rather than every call. For example, a given neighbour list may be used
for two calls. then changed to a new list used for a further two calls, and so an.
Any appropriate number of calls for such a regime (i.e. as opposed, to every one
or every two calls) may be used according to the requirements at the particular
system of situation under consideration,
Also any two or more of the above examples may occur in combination.
Thus, the terminology "on a per call basis " as used herein is to be
understood as encompassing different ways of varying the neighbour lists
according to different calls bening serviced, rather than being in.dependent.of calls,
and rather than being uniformly implemented icrespective of which calls are
being processed.

WO 2004/066655 PCT/EP2004/050036
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Although the above embodiment has been described in terms of a GSM
system, it will be appreciated that the present invention may be embodied in any
suitable cellular communications system in which neighbour position, or
equivalen characteristics, may be used to provide measurement data for
frequency planning.
The present invention may in appropriate discumstances provide, inter
alia, one more of the following advantages.
the data collection.time required to provide a given amount of useful
input for frequency planning is reduced;
the total amount of data required to be collected to provide a given
amount pf useful input for frequency planning is reduced;
reduced data analysis time;
reduce hardware and software requirements process data due to less
data;
reduction in cycle time required to provide a given amount of useful input
for frequency planning, thereby providing more representative frequency data
corresponding more closely to actual cell traffic.

WO 2004/066655 PCT/EP2004/050036
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CLAIMS
1. A method of determining frequency planning measurement data in a
cellular communications system (1), comprising.
allocating neighbour lists (208, 210, 212) to provide measurement date for
frequency planning;
wherein the neighbour lists (208,210,212) are allocated on a per call basis.
2. A method according to claim 1, wherein different neighbour lists (208, 210
212) are alloocated by the same base station (28) to different mobile stations (44,
46,48) for respective calls (204) that overlap in time.
3. A method according to claim 1 or 2, wherein 9 different neighbour list
(308,210, 212) is allocated for at least substantially each call (204) conducted by a
base station (28) of the cellular communicational system (1) compared to
respect directly preceding calls.
4. A method according to claim 1 or 2, wherein a different neighbour list
(208,, 210 212) is allocated for at least substantially each of a prede termined
number of calls conducted by a base station (28) of the cellular communication
system (1), compared for the predetennined numtaer of directly pteoeding calls.
5. A method according to any of claims 1 to 4 wherein the neighbour lists
(208, 2l0, 212,) are allocated on a per call basis such as to cover over a plurality of

WO 2004/066655 PCT/EP2004/050036
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calls (204), at least substantially all test frequencies (206) for the cell (16) served
by the base station (28).
6. A method according to claim 5, further comprising repeating, on a cyclical
basic comprising repeated pluralities of calls the neghbour lisis (208,210,212)
allocated on a per call basis covering at least substantially all the test frequencies
(206).
7. A method of frequency planning in a cellular communications system,
comprising using frequency planning measurement data acquired by a process
comprising the method according to any of claims 1 to 6.
8. A storage medium storing processor implementable instruction for
controlling one or more processors to carry out the method of any of claims 1
to 7.
9. Apparatus for determining frequency planning measurement data in a
cellular communications system (1), comprising.
means for allocating neghbour lists to provide measurement data for
frequency planning
wherein the means for allocating neighbour lists are adapted to allocate
the neighbour lists (208,210,212) on a per call basis.
10. Apparatus according to claim 10 wherein the means for allocating
neighbour lists are adapted to allocate different neighbour lists (208, 210,212)

WO 2004/066655 PCT/EP2004/050036
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from the same base station (28) to different mobile stations (44,46,48) for
respective calls (203) that overlap in time,
11. Apparatus according to claim 9 or 10 wherein the means for allocating
neighbour lists are adepted to alloocate a different neighbour list (208, 210, 212)
for at least substantially each call (204) conducted by a base station (28) of the
cellular communication system (1), compared to respective directly preceding,
calls.
12. Apparatus according to claim 9 or 10 wherein the. means for allocating
neighbour lists are adapted to allocate a different neighbour list (208, 210,, 212)
for at least substantiaally each of a predetermined number of calls conducted by a
base station (28) of the cellular communications system (1 ), compared to the
predetermined number of directly preceding calls.
13. Apparatus according to any of claims 9 to 12 wherein the means for
allocating neighbour lists are adapted to allocate the neighbour lists (208, 210,
212) on a per call basis such as to cover, over a plurality of calls (204), at least
substantially all test frequencies (206) for the cell (16) served by the base station
(28).
14. Apparatus according to claim 13, the means for allocating neighbour lists
are adapted to repeat on a cyclical basis comprising repeated pluralities of calls,
the neighbom lists (208,210,212) allocated on a per call basis covering at least
substantially all the test frequencies (206).

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15. Apparatus for frequency planning in a cellular communications system,
comprising means adapted to use frequency planning the measurement data
acquired by apparatus comprising appatous according to any of claim 9 to 14.
16. A method of determining frequency planning measurement data in a
cellular communication system substantially as hereinbefore described with
reference to the accompanying drawings,
17. Apparatus for determining frequency planning measurement data in a
cellular communications system substantially as hereinbefore described, with
reference to the accompanying drawings.

A method and apparatus for determining frequency planting measrement data in a celluer commonication sys-
tem (1) comprising allcating neighbour XXX (208, 210, 212) to provide measurment data for frequency planting wherein the
neighbour lists (208, 210, 212) are allocated on a per calf basisi. Thus different lists (208, 210, 212) may be allocated by the
same base station (28) to different mobile stadons (44, 46, 68) for respective calls (204) that overlap in time. A different neighbour
list (208, 210, 21) may be allocated for substantially each call (204) conducted by a base station (28) of the celluer communication
system (1) composed to respective directly proceding calls or may be alloacted for substntially each of predetermined number of
calls conducted by a base station (28) of the celluer communication system (1) comapred to the predetermined number of directly
preceding cells. At least substentially all test frequency (206) for the all (16) served by the base station (28) may thereby be
coverd over a phurality of calls (204).

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Patent Number

218537

Indian Patent Application Number

01374/KOLNP/2005

PG Journal Number

14/2008

Publication Date

04-Apr-2008

Grant Date

02-Apr-2008

Date of Filing

18-Jul-2005

Name of Patentee

MOTOROLA, INC.

Applicant Address

1303 EAST ALGONQUIN ROAD, SCHAUMBURG, IL 60196, U.S.A

Inventors:

#	Inventor's Name	Inventor's Address
1	HORNSEY, ANDREW	196 DROVE ROAD, SWINDON, WILTSHIRE SN1 3AG, GREAT BRITAIN

PCT International Classification Number

H04Q 3/36

PCT International Application Number

PCT/EP2004/050036

PCT International Filing date

2004-01-22

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0301546.8	2003-01-22	U.K.