Title of Invention	A METHOD FOR TRANSMITTING/RECEIVING OVERHEAD MESSAGE VIA CONTROL CHANNEL HAVING AT LEAST ONE SLOT
Abstract	A method of transmitting an overhead message via a control channel which has at least one slot is disclosed. More specifically, a base station (BS) transmits an overhead slot cycle index for providing the overhead message to a mobile station (MS) and thereafter, receives the overhead slot cycle index and determining an overhead slot cycle. Furthermore, the BS transmits the overhead message on a first slot of each overhead slot cycle according to a variable duration of the slot, and then receives the overhead message from the first slot of each overhead slot cycle according to the variable duration of the slot.

Title of Invention

A METHOD FOR TRANSMITTING/RECEIVING OVERHEAD MESSAGE VIA CONTROL CHANNEL HAVING AT LEAST ONE SLOT

Abstract

A method of transmitting an overhead message via a control channel which has at least one slot is disclosed. More specifically, a base station (BS) transmits an overhead slot cycle index for providing the overhead message to a mobile station (MS) and thereafter, receives the overhead slot cycle index and determining an overhead slot cycle. Furthermore, the BS transmits the overhead message on a first slot of each overhead slot cycle according to a variable duration of the slot, and then receives the overhead message from the first slot of each overhead slot cycle according to the variable duration of the slot.

Full Text	WO 2006/095965 PCT/KR2006/000501 TRANSMITTING OVERHEAD MESSAGE IN A MOBILE WIRELESS COMMUNICATION SYSTEM Technical Field The present invention relates to a method of transmitting an overhead message, and more particularly, to a method of transmitting an overhead message in a mobile wireless communication system by syncing the slots of the control channel frame with the slots of the overhead message frame. Background Art The present invention relates to determining transmission and receiving slots of an overhead message for broadcast/multicast transmission in a Code Division Multiple Access (CDMA) 2000 system and mobile stations. The broadcast/multicast transmission is a transmission scheme by which data can be sent from one source to multiple sources. In broadcast mode, the mobile stations in the service area can receive the broadcast data by being in broadcast receiving mode. In multicast mode, the mobile stations in the service area can receive data by subscribing to a specified multicast service. The broadcast/multicast service (BCMCS) of CDMA 2000 can be described according to the following three categories. The first category relates to carrying out the BCMCS by using a Forward Broadcast Supplemental Channel (F-BSCH) shared 2 WO 2006/095965 PCT/KR2006/000501 by the mobile stations, which are in idle mode. The F-BSCH is appropriate for the broadcast environment, and at the same time, the F-BSCH is useful in transmitting information to unspecified number of mobile stations. Since the information is transmitted to unspecified number of mobile stations, which are in idle mode, before the traffic channel allocated, portion of transmission power from a base station should be fixedly allocated so that the mobile stations near the cell borders can receive the information as well. The second category relates to carrying out the BCMCS by using a Forward Broadcast Fundamental Channel (F-BFCH) shared by the mobile stations which are in traffic receiving mode. A method of using the F-BFCH is similar to Push-To-Talk (PTT) method in that the F-BFCH is useful in transmitting the information to a specified number of mobile stations. Here, the traffic channel is first allocated before the information can be transmitted. As such, the transmission power of the F-BFCH is controlled based on the status of other mobile stations sharing the channel and therefore, power can be controlled more efficiently. The third category relates to carrying out the BCMCS by using a Forward Broadcast Supplemental Channel (F-BSCH) shared by the mobile stations, which are in traffic receiving mode. The F-BSCH is useful in transmitting information to a small number of mobile stations in broadcast receiving mode in a cell. Consequently, transmission power consumption for transmitting broadcast service is low, and less Walsh code is used. 3 WO 2006/095965 PCT/KR2006/000501 In order for the mobile stations to receive the BCMCS, each mobile station has to receive from, a base station information related to broadcast/multicast service, information related to channels used to transmit broadcast/multicast service (e.g., frequency, Walsh code, data rate, size of frame, and public long-code mask), and information related to mobile station registration, to name a few. These types of information are usually transmitted periodically via overhead messages, such as a Broadcast/Multicast Service Parameters Message (BSPM), for example. The mobile station in mode to receive the BCMCS receives an overhead message, such as the BSPM. More specifically, the BSPM can be transmitted periodically via a Paging Channel (PCH) or a Primary Broadcast Control Channel (P-BCCH). Figure 1 illustrates a method of transmitting the BSPM via the PCH. In Figure 1, the PSPM- PERIOD_INDEX is 2. Moreover, the transmission duration is defined by (B + 1) slots of the PCH, where B is determined by Equation 1. [Equation 1] In Equation 1, i is transmitted via BSPM_PERIOD_INDEX included in an Extended System Parameters Message. As for determining the first slot of each BSPM slot cycle, Equation 2 has to be satisfied. [Equation 2] 4 WO 2006/095965 PCT/KR2006/000501 In Equation 2, t represents system time of the PCH frame rait. Furthermore, the reason for dividing the system time into four slots is because the duration of the PCH frame is different from the duration of the PCH slot. That is, since the duration of the PCH frame is 20ms and the duration of the PCH slot is 80ms, the system time is divided into four slots in order to express the BSPM slot cycle in PCH slot units. According to Equation 2, as shown in Figure 1, the BSPM slot cycle can be synced with the PCH slot. Figure 2 illustrates a method of transmitting BSPM via the P-BCCH. In Figure 2, BSPM-PERIOD_INDEX is 2, and the duration of the BCCH slot is 80ms. Moreover, the duration of the BSPM slot cycle is (B +1) slots of the BCCH, and B is determined by Equation 3. [Equation 3] In Equation 3, i is transmitted via BSPM_PER1OD_1NDEX included in a Multi-Carrier Radio Resource (MC-RR) Parameters Message. To determine the first slot of each BSPM slot cycle, Equation 4 has to be satisfied. [Equation 4] 5 WO 2006/095965 PCT/KR2006/000501 In Equation 4, t represents system time of the PCH frame unit. According to Figure 2, the duration of the BCCH is 40ms and the duration of the BCCH slot is 80ms. If the first slot of the BSPM slot cycle is calculated using Equation 4, the BCCH frame slots are not in sync. This is where the problem lies. In other words, since the first slot of the BSPM slot cycle can be selected from any one of 40ms, 80ms, and 160ms based on the BCCH data rates, the first slot of the BSPM slot cycle cannot be synced with the BCCH slot In short, the slots of the overhead message transmission cycle cannot be synced with the slots of the BCCH. Disclosure of the Invention Accordingly, the present invention is directed to a method of transmitting an overhead message in a mobile wireless communication system that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide a method of transmitting an overhead message via a control channel having at least one slot. Another object of the present invention is to provide a method of receiving an overhead message via a control channel having at least one slot. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be 6 WO 2006/095965 PCT/KR2006/000501 realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method of transmitting an overhead message via a control channel having at least one slot includes transmitting an overhead slot cycle index for providing the overhead message to a mobile station (MS) and receiving the overhead slot cycle index and determining an overhead slot cycle. Furthermore, the method includes transmitting the overhead message on a first slot of each overhead slot cycle according to a variable duration of the slot, and receiving the overhead message from the first slot of each overhead slot cycle according to the variable duration of the slot. In another aspect of the present invention, a method of receiving an overhead message via a control channel having at least one slot includes receiving an overhead slot cycle index for providing the overhead message from a base station (BS) and transmitting the overhead slot cycle index. Furthermore, the method includes receiving the overhead message on a first slot of each overhead slot cycle determined by the BS according to a variable duration of the slot, and transmitting the overhead message on the first slot of each overhead slot cycle according to the variable duration of the slot. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 7 WO 2006/095965 PCT/KR2006/000501 Brief Description of Drawings The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments) of the invention and together with the description serve to explain the principle of the invention. In the drawings; FIG. 1 illustrates a method of transmitting the BSPM via the PCH; FIG. 2 illustrates a method of transmitting BSPM via the P-BCCH; FIG. 3 illustrates an example of transmitting the BSPM via the P-BCCH where BSPM_PERIOD_INDEX is 2 and the duration of the P-BCCH slot is 40ms; FIG. 4 illustrates an example of transmitting the BSPM via the P-BCCH where BSPMJPERIODJNDEX is 2 and the duration of the P-BCCH slot is 80ms; and FIG. 5 illustrates an example of transmitting the BSPM via the P-BCCH where BSPMJPERIODJNDEX is 2 and the duration of the P-BCCH is slot 160ms; FIG. 6 illustrates an example of transmitting the BSPM via the P-BCCH according to a fourth embodiment of the present invention where the duration of the P- BCCH frame of the system time is 20ms; FIG. 7 illustrates an example of transmitting the BSPM via the P-BCCH according to a fifth embodiment of the present invention where the duration of the P- BCCH frame of the system time is 20ms; and 8 WO 2006/095965 PCT/KR2006/000501 FIG. 8 illustrates an example of transmitting the BSPM via the P-BCCH according to a sixth embodiment of the present invention where the duration of the P- BCCH frame of the system time is 20ms. Best Mode for Carrying Out the Invention Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In BCCH, a maximum of eight slots can be allocated, and each BCCH can be classified by a Broadcast Control Channel Number (BCN). The BCCH having BCN of 1 can be considered as the P-BCCH and is used to transmit the overhead message. Moreover, the BCCH having BCN of 2 can be considered a Secondary BCCH (S- BCCH) and is used to transmit the broadcast message. The BSPM, which is an overhead message used for transmitting the BCMCS, can be transmitted via the P- BCCH. The transmission data rate of the BCCH is determined by the BCCH data rates included in the Sync Channel Message, and the transmission data rate can be any one of following data rates - 4,800bps, 9,600bps, and 19,200bps, for example. The BCCH frame is comprised of plurality slots whose duration is 40ms. Furthermore, the slot of the BCCH can be any one of the following duration, i.e., 40ms, 9 WO 2006/095965 PCT/KR2006/000501 80ms, or 160ms, based on the BCCH transmission data rate. That is, if the BCCH transmission data rate is 19,200bps, the duration of the BCCH slot is 40ms. Also, if the transmission data rates of the BCCH are 9,600bps and 4,800bps, the durations of the BCCH slot is 80ms and 160ms, respectively. As described above, since the duration of the BCCH slot varies based on the BCCH data rates, the first slot of the BSPM slot cycle can be modified or adjusted according to the duration of the BCCH slot. Figure 3 illustrates an example of transmitting the BSPM via the P-BCCH. In Figure 3, BSPM_PERIOD_INDEX is 2 and the duration of the P-BCCH slot is 40ms. In the present embodiment, since the duration of the P-BCCH frame corresponding to system time is 40ms and the duration of the P-BCCH slot is 40ms, the first slot of title BSPM transmission slot cycle with respect to the system time can be determined by satisfying Equation 5. [Equation 5) t mod (B+l) -0 In Equation S, B is determined as in Equation 3, and / represents the system time according to the P-BCCH frame. If the first slot of the BSPM transmission slot cycle is determined using Equation 5, the BSPM slot cycle can be synced with the P-BCCH frames as depicted in Figure 3. More specifically, for example, since the duration of the P-BCCH slot is 40ms and the duration of the P-BCCH frame of the system time is also 40ms, one-to-one 10 WO 2006/095965 PCT/KR2006/000501 correspondence exists between the two. As such, the BSPM slot cycle can be synced with the P-BCCH frames correspondingly. Figure 4 illustrates an example of transmitting the BSPM via the P-BCCH according to a second embodiment of the present invention. In Figure 4, BSPMJPERIOD_INDEX is 2, and the duration of the P-BCCH slot is 80ms. In the present embodiment, since the duration of the P-BCCH frame corresponding to the system time is 40ms and the duration of the P-BCCH slot is 80ms, there is no one-to-one correspondence as found in Figure 3. Therefore, the first slot of the BSPM transmission slot cycle with respect to the system time can be determined by satisfying Equation 6. [Equation 6] In Equation 6, B is determined as in Equation 3, and t represents the system time according to the P-BCCH frame. If the first slot of the BSPM transmission slot cycle is determined using Equation 6, the BSPM slot cycle can be synced with the P-BCCH frames as illustrated in Figure 4. More specifically, for example, since the duration of the P-BCCH slot is 80ms and the duration of the P-BCCH frame is 40ms, two P-BCCH frames of the system time, each frame having duration of 40ms, can be combined to correspond with the duration of the P-BCCH slot. 11 WO 2006/095965 PCT/KR2006/000501 Figure 5 illustrates an example of transmitting the BSPM via the P-BCCH according to a third embodiment of the present invention. In Figure 5, B SPM_PERJOD_INDEX is 2, and the duration of the P-BCCH slot is 160ms. In the present embodiment, since the duration of the P-BCCH frame corresponding to the system time is 40ms and the duration of the P-BCCH slot is 160ms, there is no one-to-one correspondence as found in Figure 3. As such, the first slot of the BSPM transmission slot cycle with respect to the system time can be determined by satisfying Equation 7. [Equation 7] In Equation 7, B is determined as in Equation 3, and t represents the system time according to the P-BCCH frame. If the first slot of the BSPM transmission slot cycle is determined by using Equation 7, the BSPM slot cycle can be synced with the P-BCCH frames as depicted in Figure 5. For example, since the duration of the P-BCCH slot is 160ms, four P-BCCH frames of the system time, each frame having duration of 40ms, can be combined to correspond with the duration of the P-BCCH slot. Figure 6 illustrates an example of transmitting the BSPM via the P-BCCH according to a fourth embodiment of the present invention where the duration of the P- BCCH frame corresponding to the system time is 20ms. Again, as in Figure 3, in Figure 6, BSPM_PERIOD_INDEX is 2 and the duration of the P-BCCH slot is 40ms. 12 WO 2006/095965 PCT/KR2006/000501 In the present embodiment, the duration of the P-BCCH frame corresponding to the system time is 20ms and the duration of the P-BCCH slot is 40ms, the first slot of the BSPM transmission slot cycle with respect to the system time can be determined by satisfying Equation 8. [Equation 8] In Equation 8, B is determined as in Equation 3, and t represents the system time in 20 frames. If the first slot of the BSPM transmission slot cycle is determined using Equation 8, the BSPM slot cycle can be synced with the P-BCCH frames as depicted in Figure 6. More specifically, for example, since the duration of the P-BCCH slot is 40ms and the duration of the P-BCCH frame corresponding to the system time is 40ms, one P- BCCH frame can be used to correspond with the duration of the P-BCCH slot of 40ms. Figure 7 illustrates an example of transmitting the BSPM via the P-BCCH according to a fifth embodiment of the present invention where the duration of the P- BCCH frame corresponding to the system time is 20ms. Again, as in Figure 4, in Figure 7, BSPM_PERIOD_INDEX is 2, and the duration of the P-BCCH slot is 80ms. In the present embodiment, since the duration of the P-BCCH frame corresponding to the system time is 40ms and the duration of the P-BCCH slot is 80ms, the first slot of the BSPM transmission slot cycle with respect to the system time can be determined by satisfying Equation 9. 13 WO 2006/095965 PCT/KR2006/000501 [Equation 9] In Equation 9, B is determined as in Equation 3, and t represents the system time in 20 frames. If the first slot of the BSPM transmission slot cycle is determined using Equation 9, the BSPM slot cycle can be synced with the P-BCCH frames as illustrated in Figure 7. More specifically, for example, since the duration of the P-BCCH slot is 80ms and. the duration of the P-BCCH frame corresponding to the system time is 40ms, two P- BCCH frames, each frame having duration of 40ms, can be grouped to correspond with the duration of the P-BCCH slot of 80ms. Figure 8 illustrates an example of transmitting the BSPM via the P-BCCH according to a sixth embodiment of the present invention where the duration of the P- BCCH frame corresponding to the system time is 20ms. Again, as in Figure 5, in Figure 8, BSPM_PERIOD_INDEX is 2, and the duration of the P-BCCH slot is 160ms. In the present embodiment, since the duration of the P-BCCH frame corresponding to the system time is 40ms and the duration of the P-BCCH slot is 160ms, the first slot of the BSPM transmission slot cycle with respect to the system time can be determined by satisfying Equation 10. [Equation 10] 14 WO 2006/095965 PCT/KR2006/000501 In Equation 10, B is determined as in Equation 3, and t represents the system time in 20 frames. If the first slot of the BSPM transmission slot cycle is determined by using Equation 10, the BSPM slot cycle can be synced with the P-BCCH frames as depicted in Figure 8. For example, since the duration of the P-BCCH slot is 160ms, four P-BCCH frames corresponding to the system time, each frame having duration of 40ms, can be combined to correspond with the duration of the P-BCCH slot of 160ms. In the descriptions of above, the BSPM is transmitted through the BCCH. However, the application of the present invention is not limited to BCCH or BSPM. The present invention can be further applied to transmission of overhead messages, which is transmitted based on a specified slot cycle, via a control channel. Here, the control channel represents the durations of the slots which change correspondingly to the data rates. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 15 WO 2006/095965 PCT/KR2006/000501 Claims 1. A method of transmitting an overhead message via a control channel having at least one slot, the method comprising: transmitting an overhead slot cycle index to allow a mobile station (MS) to determine an overhead slot cycle; receiving information of the overhead slot cycle determined by the MS based on a variable duration of the slot and the overhead slot cycle index, wherein the overhead slot cycle is repeatedly used; transmitting the overhead message on the first slot of each overhead slot cycle provided from the received information. 2. The method of claim 1, wherein the slot is any. Primary Broadcast Control Channel (P-BCCH) slot. 3. The method of claim 1, wherein the first slot of each overhead slot cycle is determined by to synchronize Primary Broadcast Control Channel (P-BCCH) frames with the overhead slot cycle, wherein a duration of a 16 WO 2006/095965 PCT/KR2006/000501 Primary Broadcast Control Channel (P-BCCH) frame is 40 ms, and wherein the variable duration of the slot is 40 ms. 3. The method of claim 1, wherein the first slot of each overhead slot cycle is determined by and wherein the variable duration of the slot is 40 ms. 4. The method of claim 3, wherein t represents system time in 20 ms frames, and B+l represents the duration of the overhead slot cycle. 5. The method of claim 3, wherein B is determined by a parameter in a Multi-Carrier Radio Resource (MC-RR) Parameters Message. 6. The method of claim 1, wherein the first slot of each overhead slot is determined by to synchronize Primary Broadcast Control Channel (P-BCCH) frames with the overhead slot cycle, wherein a duration of a Primary Broadcast Control Channel (P-BCCH) frame is 40 ms, and wherein the variable duration of the slot is 80 ms. 17 WO 2006/095965 PCT/KR2006/000501 6. The method of claim 1, wherein the first slot of each overhead slot is determined by and wherein the variable duration of the slot is 80 ms. 7. The method of claim 6, wherein t represents system time in 20 ms frames, and B+l represents the duration of the overhead slot cycle. 8. The method of claim 6, wherein B is determined by a parameter in a Multi-Carrier Radio Resource (MC-RR) Parameters Message. 9. The method of claim 1, wherein the first slot of each overhead slot is determined by to synchronize Primary Broadcast Control Channel (P-BCCH) frames with the overhead slot cycle, wherein a duration of a Primary Broadcast Control Channel (P-BCCH) frame is 40 ms, and wherein the variable duration of the slot is 160 ms. 9. The method of claim 1, wherein tile first slot of each overhead slot is determined by and wherein the variable duration of the slot is 160 ms. 18 WO 2006/095965 PCT/KR2006/000501 10. The method of claim 9, wherein t represents system time in 20 ms frames, and B+l represents the duration of the overhead slot cycle. 11. The method of claim 9, wherein B is determined by a parameter in a Multi-Carrier Radio Resource (MC-RR) Parameters Message. 12. The method of claim 1, wherein the overhead slot cycle is a Broadcast Multicast Service (BCMCS) System Parameters Message (BSPM) slot cycle. 13. A method of receiving an overhead message via a control channel having at least one slot, the method comprising: receiving an overhead slot cycle index from a base station (BS) to determine an overhead slot cycle; determining the overhead slot cycle based on a variable duration of the slot and the overhead slot cycle index received from the BS; transmitting to the BS information of the determined overhead slot cycle; and 19 WO 2006/095965 PCT/KR2006/000501 receiving the overhead message via a first slot of each overhead slot cycle. A method of transmitting an overhead message via a control channel which has at least one slot is disclosed. More specifically, a base station (BS) transmits an overhead slot cycle index for providing the overhead message to a mobile station (MS) and thereafter, receives the overhead slot cycle index and determining an overhead slot cycle. Furthermore, the BS transmits the overhead message on a first slot of each overhead slot cycle according to a variable duration of the slot, and then receives the overhead message from the first slot of each overhead slot cycle according to the variable duration of the slot.

Full Text

WO 2006/095965 PCT/KR2006/000501
TRANSMITTING OVERHEAD MESSAGE IN A MOBILE WIRELESS
COMMUNICATION SYSTEM
Technical Field
The present invention relates to a method of transmitting an overhead message,
and more particularly, to a method of transmitting an overhead message in a mobile
wireless communication system by syncing the slots of the control channel frame with
the slots of the overhead message frame.
Background Art
The present invention relates to determining transmission and receiving slots of
an overhead message for broadcast/multicast transmission in a Code Division Multiple
Access (CDMA) 2000 system and mobile stations. The broadcast/multicast
transmission is a transmission scheme by which data can be sent from one source to
multiple sources. In broadcast mode, the mobile stations in the service area can receive
the broadcast data by being in broadcast receiving mode. In multicast mode, the mobile
stations in the service area can receive data by subscribing to a specified multicast
service.
The broadcast/multicast service (BCMCS) of CDMA 2000 can be described
according to the following three categories. The first category relates to carrying out
the BCMCS by using a Forward Broadcast Supplemental Channel (F-BSCH) shared

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by the mobile stations, which are in idle mode. The F-BSCH is appropriate for the
broadcast environment, and at the same time, the F-BSCH is useful in transmitting
information to unspecified number of mobile stations. Since the information is
transmitted to unspecified number of mobile stations, which are in idle mode, before
the traffic channel allocated, portion of transmission power from a base station should
be fixedly allocated so that the mobile stations near the cell borders can receive the
information as well.
The second category relates to carrying out the BCMCS by using a Forward
Broadcast Fundamental Channel (F-BFCH) shared by the mobile stations which are in
traffic receiving mode. A method of using the F-BFCH is similar to Push-To-Talk
(PTT) method in that the F-BFCH is useful in transmitting the information to a
specified number of mobile stations. Here, the traffic channel is first allocated before
the information can be transmitted. As such, the transmission power of the F-BFCH is
controlled based on the status of other mobile stations sharing the channel and
therefore, power can be controlled more efficiently.
The third category relates to carrying out the BCMCS by using a Forward
Broadcast Supplemental Channel (F-BSCH) shared by the mobile stations, which are
in traffic receiving mode. The F-BSCH is useful in transmitting information to a small
number of mobile stations in broadcast receiving mode in a cell. Consequently,
transmission power consumption for transmitting broadcast service is low, and less
Walsh code is used.

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In order for the mobile stations to receive the BCMCS, each mobile station has
to receive from, a base station information related to broadcast/multicast service,
information related to channels used to transmit broadcast/multicast service (e.g.,
frequency, Walsh code, data rate, size of frame, and public long-code mask), and
information related to mobile station registration, to name a few. These types of
information are usually transmitted periodically via overhead messages, such as a
Broadcast/Multicast Service Parameters Message (BSPM), for example. The mobile
station in mode to receive the BCMCS receives an overhead message, such as the
BSPM.
More specifically, the BSPM can be transmitted periodically via a Paging
Channel (PCH) or a Primary Broadcast Control Channel (P-BCCH). Figure 1
illustrates a method of transmitting the BSPM via the PCH. In Figure 1, the PSPM-
PERIOD_INDEX is 2. Moreover, the transmission duration is defined by (B + 1) slots
of the PCH, where B is determined by Equation 1.
[Equation 1]

In Equation 1, i is transmitted via BSPM_PERIOD_INDEX included in an
Extended System Parameters Message.
As for determining the first slot of each BSPM slot cycle, Equation 2 has to be
satisfied.
[Equation 2]

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In Equation 2, t represents system time of the PCH frame rait. Furthermore, the
reason for dividing the system time into four slots is because the duration of the PCH
frame is different from the duration of the PCH slot. That is, since the duration of the
PCH frame is 20ms and the duration of the PCH slot is 80ms, the system time is
divided into four slots in order to express the BSPM slot cycle in PCH slot units.
According to Equation 2, as shown in Figure 1, the BSPM slot cycle can be synced
with the PCH slot.
Figure 2 illustrates a method of transmitting BSPM via the P-BCCH. In Figure
2, BSPM-PERIOD_INDEX is 2, and the duration of the BCCH slot is 80ms. Moreover,
the duration of the BSPM slot cycle is (B +1) slots of the BCCH, and B is determined
by Equation 3.
[Equation 3]

In Equation 3, i is transmitted via BSPM_PER1OD_1NDEX included in a
Multi-Carrier Radio Resource (MC-RR) Parameters Message.
To determine the first slot of each BSPM slot cycle, Equation 4 has to be
satisfied.
[Equation 4]

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In Equation 4, t represents system time of the PCH frame unit. According to
Figure 2, the duration of the BCCH is 40ms and the duration of the BCCH slot is 80ms.
If the first slot of the BSPM slot cycle is calculated using Equation 4, the BCCH frame
slots are not in sync. This is where the problem lies. In other words, since the first slot
of the BSPM slot cycle can be selected from any one of 40ms, 80ms, and 160ms based
on the BCCH data rates, the first slot of the BSPM slot cycle cannot be synced with the
BCCH slot In short, the slots of the overhead message transmission cycle cannot be
synced with the slots of the BCCH.
Disclosure of the Invention
Accordingly, the present invention is directed to a method of transmitting an
overhead message in a mobile wireless communication system that substantially
obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method of transmitting an
overhead message via a control channel having at least one slot.
Another object of the present invention is to provide a method of receiving an
overhead message via a control channel having at least one slot.
Additional advantages, objects, and features of the invention will be set forth in
part in the description which follows and in part will become apparent to those having
ordinary skill in the art upon examination of the following or may be learned from
practice of the invention. The objectives and other advantages of the invention may be

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realized and attained by the structure particularly pointed out in the written description
and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the
purpose of the invention, as embodied and broadly described herein, a method of
transmitting an overhead message via a control channel having at least one slot
includes transmitting an overhead slot cycle index for providing the overhead message
to a mobile station (MS) and receiving the overhead slot cycle index and determining
an overhead slot cycle. Furthermore, the method includes transmitting the overhead message on a first slot of each overhead slot cycle according to a variable duration of
the slot, and receiving the overhead message from the first slot of each overhead slot
cycle according to the variable duration of the slot.
In another aspect of the present invention, a method of receiving an overhead
message via a control channel having at least one slot includes receiving an overhead
slot cycle index for providing the overhead message from a base station (BS) and
transmitting the overhead slot cycle index. Furthermore, the method includes receiving
the overhead message on a first slot of each overhead slot cycle determined by the BS
according to a variable duration of the slot, and transmitting the overhead message on
the first slot of each overhead slot cycle according to the variable duration of the slot.
It is to be understood that both the foregoing general description and the
following detailed description of the present invention are exemplary and explanatory
and are intended to provide further explanation of the invention as claimed.

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Brief Description of Drawings
The accompanying drawings, which are included to provide a further
understanding of the invention and are incorporated in and constitute a part of this
application, illustrate embodiments) of the invention and together with the description
serve to explain the principle of the invention. In the drawings;
FIG. 1 illustrates a method of transmitting the BSPM via the PCH;
FIG. 2 illustrates a method of transmitting BSPM via the P-BCCH;
FIG. 3 illustrates an example of transmitting the BSPM via the P-BCCH where
BSPM_PERIOD_INDEX is 2 and the duration of the P-BCCH slot is 40ms;
FIG. 4 illustrates an example of transmitting the BSPM via the P-BCCH where
BSPMJPERIODJNDEX is 2 and the duration of the P-BCCH slot is 80ms; and
FIG. 5 illustrates an example of transmitting the BSPM via the P-BCCH where
BSPMJPERIODJNDEX is 2 and the duration of the P-BCCH is slot 160ms;
FIG. 6 illustrates an example of transmitting the BSPM via the P-BCCH
according to a fourth embodiment of the present invention where the duration of the P-
BCCH frame of the system time is 20ms;
FIG. 7 illustrates an example of transmitting the BSPM via the P-BCCH
according to a fifth embodiment of the present invention where the duration of the P-
BCCH frame of the system time is 20ms; and

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FIG. 8 illustrates an example of transmitting the BSPM via the P-BCCH
according to a sixth embodiment of the present invention where the duration of the P-
BCCH frame of the system time is 20ms.
Best Mode for Carrying Out the Invention
Reference will now be made in detail to the preferred embodiments of the
present invention, examples of which are illustrated in the accompanying drawings.
Wherever possible, the same reference numbers will be used throughout the drawings
to refer to the same or like parts.
In BCCH, a maximum of eight slots can be allocated, and each BCCH can be
classified by a Broadcast Control Channel Number (BCN). The BCCH having BCN of
1 can be considered as the P-BCCH and is used to transmit the overhead message.
Moreover, the BCCH having BCN of 2 can be considered a Secondary BCCH (S-
BCCH) and is used to transmit the broadcast message. The BSPM, which is an
overhead message used for transmitting the BCMCS, can be transmitted via the P-
BCCH.
The transmission data rate of the BCCH is determined by the BCCH data rates
included in the Sync Channel Message, and the transmission data rate can be any one
of following data rates - 4,800bps, 9,600bps, and 19,200bps, for example.
The BCCH frame is comprised of plurality slots whose duration is 40ms.
Furthermore, the slot of the BCCH can be any one of the following duration, i.e., 40ms,

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WO 2006/095965 PCT/KR2006/000501
80ms, or 160ms, based on the BCCH transmission data rate. That is, if the BCCH
transmission data rate is 19,200bps, the duration of the BCCH slot is 40ms. Also, if the
transmission data rates of the BCCH are 9,600bps and 4,800bps, the durations of the
BCCH slot is 80ms and 160ms, respectively.
As described above, since the duration of the BCCH slot varies based on the
BCCH data rates, the first slot of the BSPM slot cycle can be modified or adjusted
according to the duration of the BCCH slot.
Figure 3 illustrates an example of transmitting the BSPM via the P-BCCH. In
Figure 3, BSPM_PERIOD_INDEX is 2 and the duration of the P-BCCH slot is 40ms.
In the present embodiment, since the duration of the P-BCCH frame
corresponding to system time is 40ms and the duration of the P-BCCH slot is 40ms,
the first slot of title BSPM transmission slot cycle with respect to the system time can
be determined by satisfying Equation 5.
[Equation 5)
t mod (B+l) -0
In Equation S, B is determined as in Equation 3, and / represents the system time
according to the P-BCCH frame. If the first slot of the BSPM transmission slot cycle is
determined using Equation 5, the BSPM slot cycle can be synced with the P-BCCH
frames as depicted in Figure 3.
More specifically, for example, since the duration of the P-BCCH slot is 40ms and
the duration of the P-BCCH frame of the system time is also 40ms, one-to-one

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WO 2006/095965 PCT/KR2006/000501
correspondence exists between the two. As such, the BSPM slot cycle can be synced
with the P-BCCH frames correspondingly.
Figure 4 illustrates an example of transmitting the BSPM via the P-BCCH
according to a second embodiment of the present invention. In Figure 4,
BSPMJPERIOD_INDEX is 2, and the duration of the P-BCCH slot is 80ms.
In the present embodiment, since the duration of the P-BCCH frame corresponding
to the system time is 40ms and the duration of the P-BCCH slot is 80ms, there is no
one-to-one correspondence as found in Figure 3. Therefore, the first slot of the BSPM
transmission slot cycle with respect to the system time can be determined by satisfying
Equation 6.
[Equation 6]

In Equation 6, B is determined as in Equation 3, and t represents the system time
according to the P-BCCH frame. If the first slot of the BSPM transmission slot cycle is
determined using Equation 6, the BSPM slot cycle can be synced with the P-BCCH
frames as illustrated in Figure 4.
More specifically, for example, since the duration of the P-BCCH slot is 80ms and
the duration of the P-BCCH frame is 40ms, two P-BCCH frames of the system time,
each frame having duration of 40ms, can be combined to correspond with the duration
of the P-BCCH slot.

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Figure 5 illustrates an example of transmitting the BSPM via the P-BCCH
according to a third embodiment of the present invention. In Figure 5,
B SPM_PERJOD_INDEX is 2, and the duration of the P-BCCH slot is 160ms.
In the present embodiment, since the duration of the P-BCCH frame corresponding
to the system time is 40ms and the duration of the P-BCCH slot is 160ms, there is no
one-to-one correspondence as found in Figure 3. As such, the first slot of the BSPM
transmission slot cycle with respect to the system time can be determined by satisfying
Equation 7.
[Equation 7]

In Equation 7, B is determined as in Equation 3, and t represents the system time
according to the P-BCCH frame. If the first slot of the BSPM transmission slot cycle is
determined by using Equation 7, the BSPM slot cycle can be synced with the P-BCCH
frames as depicted in Figure 5.
For example, since the duration of the P-BCCH slot is 160ms, four P-BCCH
frames of the system time, each frame having duration of 40ms, can be combined to
correspond with the duration of the P-BCCH slot.
Figure 6 illustrates an example of transmitting the BSPM via the P-BCCH
according to a fourth embodiment of the present invention where the duration of the P-
BCCH frame corresponding to the system time is 20ms. Again, as in Figure 3, in
Figure 6, BSPM_PERIOD_INDEX is 2 and the duration of the P-BCCH slot is 40ms.

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In the present embodiment, the duration of the P-BCCH frame corresponding to
the system time is 20ms and the duration of the P-BCCH slot is 40ms, the first slot of
the BSPM transmission slot cycle with respect to the system time can be determined by
satisfying Equation 8.
[Equation 8]

In Equation 8, B is determined as in Equation 3, and t represents the system time in
20 frames. If the first slot of the BSPM transmission slot cycle is determined using
Equation 8, the BSPM slot cycle can be synced with the P-BCCH frames as depicted in
Figure 6.
More specifically, for example, since the duration of the P-BCCH slot is 40ms and
the duration of the P-BCCH frame corresponding to the system time is 40ms, one P-
BCCH frame can be used to correspond with the duration of the P-BCCH slot of 40ms.
Figure 7 illustrates an example of transmitting the BSPM via the P-BCCH
according to a fifth embodiment of the present invention where the duration of the P-
BCCH frame corresponding to the system time is 20ms. Again, as in Figure 4, in
Figure 7, BSPM_PERIOD_INDEX is 2, and the duration of the P-BCCH slot is 80ms.
In the present embodiment, since the duration of the P-BCCH frame corresponding
to the system time is 40ms and the duration of the P-BCCH slot is 80ms, the first slot
of the BSPM transmission slot cycle with respect to the system time can be determined
by satisfying Equation 9.

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WO 2006/095965 PCT/KR2006/000501
[Equation 9]

In Equation 9, B is determined as in Equation 3, and t represents the system time in
20 frames. If the first slot of the BSPM transmission slot cycle is determined using
Equation 9, the BSPM slot cycle can be synced with the P-BCCH frames as illustrated
in Figure 7.
More specifically, for example, since the duration of the P-BCCH slot is 80ms and.
the duration of the P-BCCH frame corresponding to the system time is 40ms, two P-
BCCH frames, each frame having duration of 40ms, can be grouped to correspond
with the duration of the P-BCCH slot of 80ms.
Figure 8 illustrates an example of transmitting the BSPM via the P-BCCH
according to a sixth embodiment of the present invention where the duration of the P-
BCCH frame corresponding to the system time is 20ms. Again, as in Figure 5, in
Figure 8, BSPM_PERIOD_INDEX is 2, and the duration of the P-BCCH slot is 160ms.
In the present embodiment, since the duration of the P-BCCH frame corresponding
to the system time is 40ms and the duration of the P-BCCH slot is 160ms, the first slot
of the BSPM transmission slot cycle with respect to the system time can be determined
by satisfying Equation 10.
[Equation 10]

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In Equation 10, B is determined as in Equation 3, and t represents the system time
in 20 frames. If the first slot of the BSPM transmission slot cycle is determined by
using Equation 10, the BSPM slot cycle can be synced with the P-BCCH frames as
depicted in Figure 8.
For example, since the duration of the P-BCCH slot is 160ms, four P-BCCH
frames corresponding to the system time, each frame having duration of 40ms, can be
combined to correspond with the duration of the P-BCCH slot of 160ms.
In the descriptions of above, the BSPM is transmitted through the BCCH.
However, the application of the present invention is not limited to BCCH or BSPM.
The present invention can be further applied to transmission of overhead messages,
which is transmitted based on a specified slot cycle, via a control channel. Here, the
control channel represents the durations of the slots which change correspondingly to
the data rates.
It will be apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing from the spirit or
scope of the inventions. Thus, it is intended that the present invention covers the
modifications and variations of this invention provided they come within the scope of
the appended claims and their equivalents.

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Claims
1. A method of transmitting an overhead message via a control channel
having at least one slot, the method comprising:
transmitting an overhead slot cycle index to allow a mobile station (MS)
to determine an overhead slot cycle;
receiving information of the overhead slot cycle determined by the MS
based on a variable duration of the slot and the overhead slot cycle index, wherein the
overhead slot cycle is repeatedly used;
transmitting the overhead message on the first slot of each overhead slot
cycle provided from the received information.
2. The method of claim 1, wherein the slot is any. Primary Broadcast
Control Channel (P-BCCH) slot.
3. The method of claim 1, wherein the first slot of each overhead slot cycle
is determined by to synchronize Primary Broadcast Control
Channel (P-BCCH) frames with the overhead slot cycle, wherein a duration of a

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WO 2006/095965 PCT/KR2006/000501
Primary Broadcast Control Channel (P-BCCH) frame is 40 ms, and wherein the
variable duration of the slot is 40 ms.
3. The method of claim 1, wherein the first slot of each overhead slot cycle
is determined by and wherein the variable duration of the slot is
40 ms.
4. The method of claim 3, wherein t represents system time in 20 ms
frames, and B+l represents the duration of the overhead slot cycle.
5. The method of claim 3, wherein B is determined by a parameter in a
Multi-Carrier Radio Resource (MC-RR) Parameters Message.
6. The method of claim 1, wherein the first slot of each overhead slot is
determined by to synchronize Primary Broadcast Control
Channel (P-BCCH) frames with the overhead slot cycle, wherein a duration of a
Primary Broadcast Control Channel (P-BCCH) frame is 40 ms, and wherein the
variable duration of the slot is 80 ms.

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6. The method of claim 1, wherein the first slot of each overhead slot is
determined by and wherein the variable duration of the slot is 80
ms.
7. The method of claim 6, wherein t represents system time in 20 ms
frames, and B+l represents the duration of the overhead slot cycle.
8. The method of claim 6, wherein B is determined by a parameter in a
Multi-Carrier Radio Resource (MC-RR) Parameters Message.
9. The method of claim 1, wherein the first slot of each overhead slot is
determined by to synchronize Primary Broadcast Control Channel
(P-BCCH) frames with the overhead slot cycle, wherein a duration of a Primary
Broadcast Control Channel (P-BCCH) frame is 40 ms, and wherein the variable
duration of the slot is 160 ms.
9. The method of claim 1, wherein tile first slot of each overhead slot is
determined by and wherein the variable duration of the slot is
160 ms.

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10. The method of claim 9, wherein t represents system time in 20 ms
frames, and B+l represents the duration of the overhead slot cycle.
11. The method of claim 9, wherein B is determined by a parameter in a
Multi-Carrier Radio Resource (MC-RR) Parameters Message.
12. The method of claim 1, wherein the overhead slot cycle is a Broadcast
Multicast Service (BCMCS) System Parameters Message (BSPM) slot cycle.
13. A method of receiving an overhead message via a control channel
having at least one slot, the method comprising:
receiving an overhead slot cycle index from a base station (BS) to
determine an overhead slot cycle;
determining the overhead slot cycle based on a variable duration of the
slot and the overhead slot cycle index received from the BS;
transmitting to the BS information of the determined overhead slot
cycle; and

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receiving the overhead message via a first slot of each overhead slot
cycle.

A method of transmitting an overhead message via a control channel which has at least one slot is disclosed. More
specifically, a base station (BS) transmits an overhead slot cycle index for providing the overhead message to a mobile station (MS)
and thereafter, receives the overhead slot cycle index and determining an overhead slot cycle. Furthermore, the BS transmits the
overhead message on a first slot of each overhead slot cycle according to a variable duration of the slot, and then receives the overhead
message from the first slot of each overhead slot cycle according to the variable duration of the slot.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=Xsw8lKN62v+7KWzvkZTckQ==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

278305

Indian Patent Application Number

3264/KOLNP/2007

PG Journal Number

53/2016

Publication Date

23-Dec-2016

Grant Date

20-Dec-2016

Date of Filing

05-Sep-2007

Name of Patentee

LG ELECTRONICS INC.

Applicant Address

20, YOIDO-DONG, YOUNGDUNGPO-GU, SEOUL

Inventors:

#	Inventor's Name	Inventor's Address
1	KIM YOUNG-JUN	303, 398-17, ANYANG 8-DONG, MANAN-GU,, ANYANG-SI, GYEONGGI-DO, 430-018
2	AN JONG HOE	1305-808, SINSIGAJI APT., 13-DANJI, SINJEONG 6(YUK)-DONG,, YANGCHEON-GU, SEOUL 158-773
3	KYUNG CHAN HO	7/8, 994-45, HOGYE 1(IL)-DONG, DONGAN-GU,, ANYANG-SI, GYEONGGI-DO 431-081
4	YUN YOUNG WOO	DOOSAN APT., 114-1502, PONGCHEONBON- DONG,, KWANAK-GU, SEOUL 151-781

PCT International Classification Number

H04Q 7/38,H04L 12/18

PCT International Application Number

PCT/KR2006/000501

PCT International Filing date

2006-02-13

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102005-0020225	2005-03-10	Republic of Korea