MXPA97001214A - A method and system to implement a back-back digital control channel, within a celu telecommunications network - Google Patents

Abstract

The present invention relates to a method for implementing a backup digital control channel within a cellular telecommunications network having a plurality of cells, each of the cells has an associated base station, each of the base stations is controlled by a mobile switching center, each of the base stations has a plurality of transmitters, and one of the transmitters in each of the base stations transmits a digital control channel, the method comprises the steps of: detecting through one of the base stations a failure of the digital control channel in the same, identify by the base station with the digital control channel that has failed, a first transmitter of the plurality of transmitters, the first transmitter has the channel of digital control that has failed to detect in the mobile switching center a time slot available in a second transmitter of the plurality of transmitter is in the base station with the digital control channel that has failed, reconfigure from the mobile switching center, the time slot available as the backup digital control channel to replace the failed digital control channel; the mobile switching center to a neighboring cell that the digital control channel has failed, and inform by means of the mobile switching center through an exchange of a neighboring external cell controlled by the neighboring mobile switching center, that the Digital backup control has replaced the digital control channel that has failed

Description

A METHOD AND SYSTEM TO IMPLEMENT A CONTROL CHANNEL DIGITAL BACKUP WITHIN A CELLULAR TELECOMMUNICATIONS NETWORK " A portion of the exposition of this patent document contains material to which a claim of copyright protection is made. The owner of the copyright has no objection to the facsimile reproduction by any person of the patent document or patent exposition as it appears in the archives or patent registers of the Patent and Trademark Office, but reserves all the others rights.

BACKGROUND TECHNICAL FIELD OF THE INVENTION The present invention relates to a cellular telecommunication network and, more particularly, to a backup to the digital control channel of the network.

DESCRIPTION OF THE RELATED ART In modern cellular telecommunication networks, the networks are divided into cells that give service to a defined area for mobile stations. Each cell contains a base station that transmits and receives the voice and control information to and from the mobile stations that are located within the coverage area of the cell. Each of the cells employs a separate control channel for retransmitting the control information to the mobile stations. Currently / cellular telecommunications networks use analog control channels for the passage of control information. Analog technology, however, limits the total number of available channels within the mobile frequency spectrum to 832, approximately 21 of which can be used as control channels. Analog technology also limits the allocation of a control channel or subscriber communications to only analog radio channel. Digital technology has been introduced to solve many of the limitations and problems associated with analog technology, therefore, the cellular telecommunication industry (which will be referred to below as the cellular industry) is moving quickly to finalize a standard for a Digital Control Channel (DCCH) that has full frequency agility throughout the frequency spectrum of the mobile phone.

In digital cellular networks, a plurality of subscriber's voice channels or control channels can be assigned to each radio frequency through Time Division Multiple Access (TDMA) technology. In TDMA technology, each channel that is broadcasting at a specific frequency is divided into a plurality of time slots. The signals of the subscriber's control or communication channel are converted into a digital format and divided into bursts of short communications. Each burst is marked with an identifier, assigned to a time interval and diffused in an interspersed manner with other bursts on the same frequency. At the receiving end, the identifiers are used to reconstruct all communication from individual bursts. The current version of the cellular industry standard for a Digital Control Channel (DCCH) is described in Project Number 3011-2 of Interim Standard IS-54-C of EIA / TIA, "Dual Mode Mobile System Station Cellular - Compatibility Standard of the Base Station "dated April 12, 1994, which is incorporated herein by reference. As mentioned above the DCCH provides full frequency agility across the entire mobile phone frequency spectrum and thus greatly increases the number of available control channels. The DCCH transmits the information of control to the mobile stations together with the information about the neighboring cells (NCELLS). The DCCH performs the function of a service access point for mobile subscribers to the cells within a cellular telecommunications network. Therefore, if a DCCH fails, the services that are provided through the cells are lost, resulting in decreased revenues for the network operator. In cellular telecommunication networks, mobile calls must be processed on a continuous basis. Therefore, it is critical that there are base stations that operate on a continuous basis. If a DCCH is implemented in a transmitter of the base station and the transmitter subsequently fails, then all mobile stations within the base station cell are no longer able to establish new communications with the base station. Therefore, it is desirable that the base stations have a backup control channel to ensure that a high level of service is maintained in the associated cell. Currently, the cellular industry uses a hardware solution to provide a backup for a primary DCCH that has failed. The hardware solution can be, for example, a conventional configuration of the frequency agile transmitter combiners to which reference will be made below as a self-tuner. Typically, the auto-tuner is physically connected to the transmitter that failed where the primary DCCH was used. Once the transmitter failure is detected, all DCCH operations within the transmitter are physically transferred to the auto-tuner through a hardware switch. There are several disadvantages to using an auto-tuner to perform the DCCH backup function. First, each base station that wants a backup for its DCCH should be modified with the inclusion of an auto-tuner. Second, any of the changes or revisions to the logic for the auto-tuner requires changing the internal components of the hardware for each auto-tuner. Finally, any changes or revisions to the hardware of an auto-tuner often require personal service to physically visit each base station that has an auto-tuner in order to make revisions or changes. This is a costly and useless solution. Having a backup DCCH that overcomes these disadvantages would be a distinct advantage. The present invention provides this solution.

COMPENDIUM OF THE INVENTION The present invention is a computer program to carry out the function of backing a Digital Control Channel. { DCCH). If the DCCH fails, then the computer program finds any available time slot on any transceiver within the base station and reconfigures the time interval to implement a backup DCCH. Any of the updates required to the computer program can be carried out remotely through a mobile switching center (MSC) associated with the appropriate base station. In one aspect, the present invention is a method for implementing a backup digital control channel within a cellular telecommunications network having a plurality of cells with each of the cells having an associated base station, each of the stations of base has a plurality of transmitters, and one of the transmitters in each of the base stations transmits a digital control channel. The method of the present invention includes detecting a failure of a primary digital control channel within one of the base stations, and identifying a first transmitter of the plurality of transmitters in the base station with the digital control channel that has failed , which has the digital control channel that failed.

Then, an interval of time available in the second transmitter of the plurality of transmissions at the base station is detected with the digital control channel that failed, and the available time slot is reconfigured as a backup digital control channel to replace to the digital control channel that failed. The neighboring cells and neighboring external cells are then informed that the backup digital control channel has replaced the digital control channel that failed. In another aspect, the invention is present in a system for implementing a backup digital control channel within a cellular telecommunications network comprising means for detecting a failure of a primary digital control channel within one of the base stations and means to identify a first transmitter of the plurality of transmitters in the base station with the digital control channel that failed, which has the digital control channel that has failed. The system also includes means for detecting a time slot available in a second transmitter from the plurality of transmitters in the base station, with the digital control channel that failed and means for reconfiguring the available time slot as the digital control channel of backup to replace the digital control channel that has failed, the system also includes means to inform the neighboring cells and neighboring external cells that the backup digital control channel has replaced the failed digital control channel.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art with reference to the following drawings, together with the accompanying specification in which: Figure 1 is a diagram of a system of conventional cellular radio communications of the type to which the present invention relates generally; Figures 2A to 2F are a flow chart illustrating the steps of a computer program to implement a software Digital Control Channel (DCCH) backup function for a primary DCCH that has failed within one of the C1- cells C10 of Figure 1; and Figures 3A to 3D are a sequence diagram illustrating the signals and the pseudocode for implementing a preferred embodiment of the backup function of the DCCH of Figures 2A through 2F.

DETAILED DESCRIPTION OF THE MODALITIES Referring first to Figure 1, a conventional cellular radio communication system of the type to which the present invention relates is generally illustrated. In Figure 1, an arbitrary geographic area can be divided into a plurality of contiguous radio coverage areas or cells C1-C10. Even though the system of Figure 1 is shown illustratively to include only ten cells, it should be clearly understood that in practice, the number of cells will be much larger. Associated with and placed within each of the Cl-ClO cells is a base station designated as a corresponding one of a plurality of base stations B1-B10. Each of the base stations B1-B10 includes a transmitter, a receiver and a base station controller, as is well known in the art. In Figure 1, the base stations B1-B10 are illustratively located in the center of each of the Cl-ClO cells respectively and are equipped with omni-directional antennas. However, in other configurations of a cellular radio system, the base stations B1-B10 are located near the periphery or otherwise remote from the centers of the Cl-ClO cells and can Illuminate cells C1-C10 with radio signals either omni-directional or directionally. Therefore, the representation of the cellular beam system of Figure 1 is for purposes of illustration only and is not intended as a limitation on the possible implementations of the cellular radio system within which the method and system of the cell can be implemented. present invention. Still referring to Figure 1, a plurality of MI-MIO mobile stations can be found within cells C1-C10. Again, only 10 mobile stations are shown in Figure 1 but it should be understood that the actual number of mobile stations will be much greater in practice and will invariably greatly exceed the number of base stations. In addition, since none of the mobile stations M1-M10 can be found in some of the cells C1-C10, the presence or absence of the mobile stations MI-MIO in any specific cell of the cells C1-C10 must be understood to depend, in the practice of the individual desires of the mobile stations M1-M10, which can wander from one location in the cell to another or from a cell to an adjacent cell or neighboring cell, and even from a cellular radio system to which it is given service by the mobile switching center to another of these systems.

Each of the mobile stations M1-M10 is capable of initiating or receiving a telephone call through one or more of the base stations B1-B10, and an associated mobile switching center (MSC). A mobile switching center MSCl is connected via the communication packages, eg, cables to each of the illustrative base stations B1-B4 and to a fixed public switched telephone network (PSTN) (not shown) or to a network similar fixed that can include an integrated system digital network (ISDN) installation. A mobile switching center MSC2 is connected via communication links, eg, cables to each of the illustrative base stations B5-B10 and to the fixed public switched telephone network (PSTN) not illustrated or a similar fixed network which may include an integrated system digital network installation ( ISDN). The related connections between the mobile switching center MSCl and MSC2 and between the mobile switching centers MSCl and MSC2 and PSTN or ISDN are not fully shown in Figure 1, but are well known to those skilled in the art. Each of the cells C1-C10 is allocated from a plurality of speech or conversation channels and at least one control or access channel. The control channel is used to control or supervise the operation of the mobile stations by means of the transmitted information to and received from those units. This information may include incoming call signals, outgoing call signals, messenger search signals, messenger search response signals, location registration signals, voice channel assignments, maintenance instructions, and reselection instructions. cell as the mobile station marches out of the radio coverage of one cell and into the radio coverage and of another cell. The control channels can then be operated either in an analog or digital mode or a combination thereof. Figures 2A to 2F show a flow chart illustrating the steps of a computer program to implement a software Digital Control Channel (DCCH) backup function for a primary DCCH that has failed within one of the C1- cells C10 of Figure 1. Referring now to Figure 2A, the program begins at step 202 and continues to step 206 during the detection of a DCCH fault within a base station of one of the cells C1-C10 (FIG. 1) . Once the DCCH failure has been detected, the program determines whether or not a digital equipment is available within the associated base station of the cell with the DCCH that has failed. If no digital equipment is available, the problem ends in step 228. However, if in step 206 it is determines that more digital equipment is available, then the program selects the digital equipment and continues to step 208. In step 208, the program determines whether or not a free time slot is available within any of the channels in the selected equipment . If it is determined that a free time slot is not available, then the program proceeds to step 210 where a time slot is available within a specified channel. The program then moves to step 212 where the program selects the available time interval. However, if in step 208 it is determined that a free time slot is available, then the program continues directly to step 212, where the program selects the available time slot. The program then proceeds to step 214 where the selected time interval is reconfigured as a new DCCH. The program then proceeds to step 216 where it is determined whether or not the base station of the cell with the failed DCCH contains an analog control channel of the frequency shift key (FSK). If it is determined that the base station contains an FSK control channel, then the problem advances to step 218 where the FSK is updated with a number of channel and a digital verification color code of the new DCCH. The program then moves to step 220. However, if in step 216 it is determined that the base station does not contain an FSK control channel, then the program continues directly to step 220. In step 220 it is determined whether the Base station contains or does not contain digital traffic channels (DTCs). If it is determined that the base station contains the DTCs, then the program proceeds to step 230 in Figure 2B. If in step 220 it is determined that the failed cell does not contain the DTCs, then the program proceeds to step 222. Referring now to Figure 2B, in step 230, a selected DTC is updated with the channel number and the digital verification color code (DVCC) of the new DCCH, as well as a digital encoder (CDL) of the DTC. The program then proceeds to step 232 where it is determined if all the DTCs within the base station have been updated. If it is determined that all DTCs within the cell have been updated, then the program selects a new DTC and returns to step 230 where it repeats the update process. If in step 232 it is determined that all the DTCs within the base station have been updated, then the program continues to step 222 in Figure 2A.

Referring again to Figure 2A, in step 222, the program determines whether or not the base station contains analog voice channels (AVCs). If it is determined that the base station contains analog voice channels, then the program proceeds to step 234 in Figure 2C. However, in step 222, it is determined if the base station does not contain the AVCs and then the program advances to step 224. Referring now to Figure 2C, in step 234, a selected AVC with the number is updated. channel and the digital verification color code (DVCC) of the new DCCH. The program then proceeds to step 236 where it is determined whether the AVCs have been updated within the base station or not. If it is determined that all AVCs within the base station have not been updated, then the program selects a new AVC, returns to step 234 and repeats the update process. If it is determined in step 236 that all the AVCs within the base station have been updated, then the program proceeds to step 224 in Figure 2A. Referring again to Figure 2, in step 224 it is determined whether or not the cell was serviced by the base station with the failed DCCH having any of the neighboring cells (NCELLS). If the cell has NCELLS, then the program advances to the step 238 in Figure 2D. If the cell does not have NCELLS, then the program proceeds to step 226 in Figure 2E. Referring now to Figure 2D, in step 238, the DCCH neighbor list for a selected NCELL is updated with the channel number and the DVC of the new DCCH, and the program advances to step 240. In step 240, it is determined whether or not the DCCH channel number is a Measurement Channel Number (MCHNR) for a Mobile Station Assisted Delivery (MAHO), as defined in IS-54. If the channel number DCCH is determined to be an MCHNR for an MAHO, then the program advances to step 242. However, if it is determined in step 240 the channel number DCCH is not an MCHNR for an MAHO, then the program proceeds to step 248. In step 242, an MAHO list of the selected DTCs is updated and the program proceeds to step 246 where it is determined whether the DTCs have been updated within the selected NCELL cell. If it is determined that all DTCs within the selected NCELL cell have been updated, then the program proceeds to step 248. If step 246 is determined that all DTCs within the selected NCELL cell have not been updated, then the program select a new DTC at 247, return to step 242 and repeat the update process. In step 248 it determines whether the NCELLS have been updated or not. If it is determined that all NCELLS have not been updated, then the program selects a new NCELLS at 249, returns to step 238 and repeats the process described above in relation to step 238. If step 248 is determined that all NCELLS are have updated, then the program progresses to step 226 in Figure 2E. Referring now to Figure 12, in step 226 it is determined whether or not the cell that has been serviced by the base station with the failed DCCH has neighboring external cells (NOCELLS). A NOCELLS is defined as a neighbor cell that is controlled by a different MSC than the cell with the DCCH that failed. In Figure 1, for example, C7 is a NOCELL to Cl because C7 is a neighbor cell that is controlled by MSC2, while Cl is controlled by MSC1. If it is determined that the cell has NOCELLS, then the program proceeds to step 250 in Figure 2F. If it is determined in step 226 that the cell does not have NOCELLS, then the program ends in step 228. Referring now to Figure 2F, in step 250 the selected neighbor mobile switching center (NMSC) of the new point is informed DCCH service access, and the program proceeds to step 252 where a selected NOCELL has its DCCH neighbor list updated with the DVCC channel number of the new DCCH. The program then proceeds to step 254 where it is determined whether or not the channel number of the new DCCH is a Measurement Channel Number (MCHNR) for a Delivery Helped by a Mobile Station (MAHO). If it is determined that the channel number of the new DCCH is MCHNR for MAHO, then the program proceeds to step 256. However, if it is determined in step 254 that the channel number of the new DCCH is not MCHNR for MAHO, then the program proceeds to step 260. In step 256, the list of MAHO DTCs of the selected NOCELL is updated, and the program proceeds to step 258. In step 258, it is determined whether the DTCs of all selected NOCELL have been or are not updated. If all selected NOCELL DTCs have not been updated, then the program selects a new DTC from the NOCELL selected at 259, returns to step 256 and repeats the update process. If it is determined in step 258 that all the NOCELL DTCs have been updated, then the problem proceeds to step 260 where it is determined whether the NOCELLS have been updated or not. If all NOCELLS have not been updated, then the program selects a new NOCELL from the cell with the DCCH that failed at 261, returns to step 252 and repeats the process described above in relation to step 252. If determined in step 260 that all the NOCELLS have been updated, then the program proceeds to step 262 where it is determined whether or not all the NMSCs have been updated. If all the NMSCs have not been updated, then the program selects a new NMSC at 263, returns to step 250 and then repeats the process described above in relation to step 250. If it is determined in step 262 that all NMSCs have been updated, then the program returns to Figure 2E and terminates step 228. Figures 3A-3D show a sequence diagram illustrating the signals and the pseudocode to implement a preferred embodiment of the DCCH backup function of Figures 2A- 2F. In particular, Figures 3A-3C illustrate actions that are taken within a control MSC during the detection of a DCCH fault. Figure 3D illustrates actions that are taken within neighboring MSCs. Referring first to Figure 3A, during the determination that a DCCH failure has occurred within a base station, a signal is sent to the control MSC of the base station at 302. The control MSC performs the steps 206 to 214 as described above in relation to Figures 2A-2F. At 304, the control MSC sends the MDEQDATA signal to the base station indicating that the selected time interval must be reconfigured as the new DCCH. At 306, the control MSC sends an MDCCHDATA signal and a DPMCCDATA signal to the base station with the DCCH fault. The base station responds to the two signals as described above in relation to steps 216 to 218 of Figure 2A. Referring now to Figure 3B at 310, the control MSC sends an MDVCDATA signal to the base station with the DCCH fault. The base station responds to the signal as described above in relation to step 230 of Figure 2B and steps 230-232 of Figure 2B. At 312, the control MSC sends a DPMVCDATA signal to the base station. The base station responds to the signal as described above in relation to step 222 of Figure 2A and steps 234-236 of Figure 2D. Referring now to Figure 3C, at 314, the control MSC sends an MDCCHDATA signal to each neighbor cell associated with the base station with the DCCH failure. Each neighbor cell responds to the signal as described above in step 224 of Figure 2A and steps 238-248 of Figure 2D. At 316, the control MSC sends an MDVCDATA signal to each neighboring cell associated with the base station with the DCCH failure. Each neighbor cell responds to the signal as described above in step 224 of Figure 2A and steps 238-248 of Figure 2D.

Referring now to Figure 3D at 318, the control MSC sends a DCC_SAP_CHANGE signal to each neighbor MSC of the NOCELLS. A neighbor MSC responds at 320 by sending a DCCHDATA signal and a DCDATA signal to each of the neighboring external cells. The neighboring MSC and the associated neighboring external cells respond to the signals as described above in relation to step 226 of Figure 2E and steps 250-264 of Figure 2F. The flow charts of Figures 2A-2F as well as the sequence diagrams of Figures 3A-3D are functional if the cellular telecommunications network is implemented under the IS-54 standard, the Global Standard for Mobile Communications (GSM) or the Japanese Standard (PDC). The process is essentially the same for GSM or PDC; IS-54 adds specific steps dealing with analog control channels to detect frequency offset (FSK CCs) and analog voice channels (AVCs). In the decision steps involving these specific implementations of IS-54, the process determines that the base station of the cell with the failed DCCH does or does not contain an FSK CC or AVCs. If it does, then the program updates those implementations of IS-54. If not, the program continues with the steps that are common for all three standards.

It has been believed, therefore, that the operation and construction of the present invention will be apparent from the foregoing description. Although the method shown and described has been characterized as being preferred, it will be readily apparent that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.

Claims (22)

R E I V I N D I C A C I O N E S:

1. A method for implementing a backup digital control channel within a cellular telecommunication network having a plurality of cells, each of the cells having an associated base station, each of the base stations being controlled by a hub. mobile switching, each of the base stations has a plurality of transmitters, and one of the transmitters in each of the base stations transmits a digital control channel, the method comprises the steps of: detecting through one of the stations of base a failure of the digital control channel in it; identify by the base station with the digital control channel that has failed, a first transmitter of the plurality of transmitters, the first transmitter has the digital control channel that has failed; detecting in the mobile switching center a time slot available in a second transmitter from the plurality of transmitters in the base station with the digital control channel that has failed; reconfigure from the mobile switching center, the time interval available as the channel of digital backup control to replace the digital control channel that has failed; reporting via the mobile switching center to a neighboring cell that the backup digital control channel has replaced the failed digital control channel; and reporting through the mobile switching center through an exchange of an adjacent external cell controlled by the neighboring mobile switching center, that the backup digital control channel has replaced the failed digital control channel.

The method according to claim 1, further comprising the step of: updating via the mobile switching center, a frequency shift keyboard control channel with the base station having the digital control channel that has failed detected, with a digital verification color code and a channel number of the digital backup control channel.

The method according to claim 2, further comprising the step of: updating via the mobile switching center, a digital traffic channel within the base station having the digital control channel that has failed, with the digital verification color code and the channel number of the backup digital control channel.

The method according to claim 3, further comprising the step of: updating via the mobile switching census, a digital traffic channel within the base station that has the digital control channel that has failed, with a digital encoder of the backup digital control channel.

The method according to claim 4, further comprising the step of: updating via the mobile switching center, an analog voice channel within the base station having the digital control channel that has failed with the code color digital verification and the channel number of the digital backup control channel.

The method according to claim 1, wherein the step to inform a neighbor cell includes the step of: updating a neighboring list of the digital control channel of the neighboring cell with a channel number through the mobile switching center. and a digital verification color code of the backup digital control channel.

7. The method according to claim 6, wherein the step of informing a neighbor cell includes the step of informing via the mobile switching center to a neighboring cell including a digital traffic channel having a delivery list aided by the mobile station.

The method according to claim 7, wherein the step of updating a neighboring list of the digital control channel of the neighboring cell includes the step of updating via the mobile switching center the delivery list aided by the mobile station of the neighboring cell. digital traffic channel with the digital control channel of blanching.

9. The method according to claim 1, where the step of informing a neighboring external cell includes the steps of: informing through the mobile switching center to the neighboring mobile switching center that has control through the neighboring external cells that the backup digital control channel has replaced to the digital control channel that has failed; and updating through the neighboring mobile switching center a digital control channel view of the neighboring external cell with a channel number and a code of Digital verification color of the digital backup control channel.

The method according to claim 9, wherein the step of informing a neighboring external cell includes the step of reporting through the neighboring mobile switching center to a neighboring external cell including a digital traffic channel having a list of delivery aided by the mobile station.

The method according to claim 10, wherein the step of updating a digital control channel list with the neighbor cell includes the step of updating the delivery list aided by the mobile station of the neighboring mobile switching center by the mobile station of the neighboring cell. digital traffic channel, with the backup digital control channel.

12. A system for implementing a backup digital control channel within a cellular telecommunications network having a plurality of cells, each of the cells has an associated base station, each of the base stations has a plurality of transmitters and one of the transmitters in each of the base stations transmits a digital control channel, the system comprising: a means for detecting a failure of the digital control channel within one of the base stations; a means for identifying a first transmitter of the plurality of transmitters in the base station with the digital control channel that has failed, the first transmitter has the digital control channel that has failed; means for detecting a time interval available in a second transmitter from the plurality of transmitters in the base station, with the digital control channel having failed; means for reconfiguring the available time slot as a backup digital control channel to replace the failed digital control channel; a means to inform a neighboring cell that the backup digital control channel has replaced the failed digital control channel; and a means for informing an adjacent external cell controlled by a neighboring mobile switching center, that the backup digital control channel has replaced the failed digital control channel.

The system according to claim 12, further comprising: means for updating a frequency shift key control channel within the base station having the digital control channel that has failed detected, with a digital verification color code and channel number of the backup digital control channel.

The system according to claim 12, further comprising: means for updating a digital traffic channel within the base station having the digital control channel that has failed, with the digital verification color code and the channel number of the backup digital control channel.

15. The system according to claim 14, further comprising: means for updating a digital traffic channel within the base station that has the digital control channel that has failed, with a digital encoded placeholder and the channel of digital backup control.

The system according to claim 15, further comprising: means for updating an analog voice channel within the base station having the digital control channel that has failed, with the digital verification color code and the channel number of the backup digital control channel.

17. The system according to claim 12, wherein the means for reporting to a neighbor cell includes: a means for updating a neighboring list of the digital control channel of the neighboring cell with a channel number and a digital verification color code of the backup digital control channel.

18. The system according to claim 17, wherein the neighbor cell includes a digital traffic channel that has a delivery list aided by a mobile station.

19. The system according to claim 18, wherein the means for updating a neighboring list of the digital control channel of the neighboring cell includes: means for updating the delivery list aided by the mobile station of the digital traffic channel of the neighboring cell, with the digital control channel of the neighboring cell. backup The system according to claim 12, wherein the means for reporting to a neighboring external cell includes: means for informing a neighboring mobile switching center that has control through the external cell neighbor, that the backup digital control channel has replaced the digital control channel that has failed; and means for updating a digital control channel list of the neighboring external cell with a channel number and a digital verification color code of the digital backup control channel. The system according to claim 20, wherein the neighbor external cell includes a digital traffic channel having a delivery list aided by a mobile station. The system according to claim 21, wherein the means for updating a digital control channel list of the neighboring external cell includes: means for updating the assisted delivery list by mobile station of the digital traffic channel of the neighboring external cell, with the digital backup control channel.