Exchange of system and terminal capabilities over the same analog control channel

Claims

What is claimed is:

1. A method for exchanging protocol support information between a base station and a mobile station over at least one analog control channel, comprising the steps of:

transmitting first information from the base station over a first analog control channel, the first information specifying at least one protocol supported by the base station; and

receiving the transmitted first information at the mobile station and, in response thereto, transmitting second information from the mobile station to the base station over a second analog control channel, the second information specifying at least one protocol supported by the mobile station;

wherein prior to the performance of the step of receiving, steps are performed of detecting a power-on condition of the mobile station; and initializing values of variables Protocol Capability System Id (PCSID.sub.s), Base Station Protocol Capability (BSPC.sub.s), and Base Station Core Analog Roaming Protocol (BSCARP.sub.s) stored in a memory of the mobile station.

2. A method as set forth in claim 1, wherein the at least one protocol supported by the base station includes at least one of a predefined air-interface protocol and a predefined core analog roaming protocol supported by the base station.

3. A method as set forth in claim 1, wherein the at least one protocol supported by the mobile station includes at least one of a predefined air-interface protocol and a predefined core analog roaming protocol supported by the mobile station.

4. A method as set forth in claim 1, wherein the second information also specifies function capability features that are supported by the mobile station.

5. A method as set forth in claim 1, wherein the second information also specifies function capability features that are not supported by the mobile station.

6. A method as set forth in claim 4, wherein the function capability features include at least one of core analog protocol-related functions and dual-mode protocol-related functions.

7. A method for exchanging protocol support information between a base station and a mobile station over at least one analog control channel, comprising the steps of:

transmitting first information from the base station over a first analog control channel, the first information specifying at least one protocol supported by the base station; and

receiving the transmitted first information at the mobile station and, in response thereto, transmitting second information from the mobile station to the base station over a second analog control channel, the second information specifying at least one protocol supported by the mobile station;

wherein the second information also specifies function capability features that are supported by the mobile station;

wherein the function capability features include at least one of core analog protocol-related functions and dual-mode protocol-related functions; and

wherein the core analog protocol-related functions include Calling Line Identification, Call Waiting, splash ringing with abbreviated alert, and Message Waiting.

8. A method as set forth in claim 1, wherein, for a case in which the second information specifying the at least one protocol supported by the mobile station was already transmitted by the mobile station to the base station, the mobile station does not respond to receiving the first information by again transmitting the second information.

9. A method as set forth in claim 1, wherein the step of transmitting the first information includes transmitting an Overhead Message Train (OMT) from the base station, the OMT including a Global Action Overhead Message (GAOM), the GAOM including an Action Type Parameters Global Action Message (ATPGAM) specifying the at least one protocol supported by the base station.

10. A method for exchanging protocol support information between a base station and a mobile station over at least one analog control channel, comprising the steps of:

transmitting first information from the base station over a first analog control channel, the first information specifying at least one protocol supported by the base station; and

receiving the transmitted first information at the mobile station and, in response thereto, transmitting second information from the mobile station to the base station over a second analog control channel, the second information specifying at least one protocol supported by the mobile station;

wherein the step of transmitting the first information includes transmitting an Overhead Message Train (OMT) from the base station, the OMT including a Global Action Overhead Message (GAOM), the GAOM including an Action Type Parameters Global Action Message (ATPGAM) specifying the at least one protocol supported by the base station; and

wherein the ATPGAM includes a Base Station Protocol Capability (BSPC) data field specifying at least one predefined air-interface protocol supported by the base station, and wherein the ATPGAM further includes a Base Station Core Analog Roaming Protocol (BSCARP) data field specifying at least one core analog roaming protocol supported by the base station.

11. A method as set forth in claim 1, wherein the second information includes a Reverse Control Channel (RECC) message, the RECC message including a Protocol Capability Registration Message (PCRM) that includes at least three Words, one of the Words including a First Word of the Protocol Capability Registration Message (FWPCRM) that specifies the at least one protocol supported by the mobile station.

12. A method as set forth in claim 11, wherein other ones of the Words of the PCRM include at least one of an Abbreviated Address Word (Word A), an Extended Address Word (Word B), and an Authentication Word (Word C).

13. A method for exchanging Protocol support information between a base station and a mobile station over at least one analog control channel, comprising the steps of:

transmitting first information from the base station over a first analog control channel, the first information specifying at least one protocol supported by the base station; and

receiving the transmitted first information at the mobile station and, in response thereto, transmitting second information from the mobile station to the base station over a second analog control channel, the second information specifying at least one protocol supported by the mobile station;

wherein the second information includes a Reverse Control Channel (RECC) message, the RECC message including a Protocol Capability Registration Message (PCRM) that includes at least three Words, one of the Words including a First Word of the Protocol Capability Registration Message (FWPCRM) that specifies the at least one protocol supported by the mobile station;

wherein other ones of the Words of the PCRM include at least one of an Abbreviated Address Word (Word A), an Extended Address Word (Word B), and an Authentication Word (Word C); and

wherein the Extended Address Word (Word B) includes information specifying whether or not the Authentication Word (Word C) is included in the PCRM.

14. A method as set forth in claim 13, wherein the information specifying whether or not the Authentication Word (Word C) is included in the PCRM is specified by an ORDER data field, an ORDQ data field, and a MSG.sub.-- TYPE data field of the Extended Address Word (Word B).

15. A method as set forth in claim 11, wherein the FWPCRM includes information specifying whether the FWPCRM is the first word of the PCRM, and whether other words follow the FWPCRM in the PCRM.

16. A method for exchanging protocol support information between a base station and a mobile station over at least one analog control channel, comprising the steps of:

transmitting first information from the base station over a first analog control channel, the first information specifying at least one protocol supported by the base station; and

receiving the transmitted first information at the mobile station and, in response thereto, transmitting second information from the mobile station to the base station over a second analog control channel, the second information specifying at least one protocol supported by the mobile station;

wherein the second information includes a Reverse Control Channel (RECC) message, the RECC message including a Protocol Capability Registration Message (PCRM) that includes at least three Words, one of the Words including a First Word of the Protocol Capability Registration Message (FWPCRM) that specifies the at least one protocol supported by the mobile station; and

wherein the FWPCRM includes at least one of a Mobile Station Protocol Capability (MSPC) data field, a Mobile Station Core Analog Roaming Protocol (MSCARP) data field, a Calling Line Identification (CLI) data field, a Call Waiting (CWT) data field, a Message Waiting Notification (MWN) data field, an AA data field, and at least one dual-mode function information field, the MSPC data field specifying at least one air-interface protocol supported by the mobile station, the MSCARP data field specifying at least one core analog roaming protocol supported by the mobile station, the CLI field specifying whether or not the mobile station supports a Call Waiting function, the CWT data field specifying whether or not the mobile station supports a Call Waiting function, the MWN data field specifying whether or not the mobile station supports a Message Waiting function, the AA data field specifying whether or not the mobile station supports a splash ringing with abbreviated alert function, and the at least one dual-mode function information field specifying whether or not the mobile station supports at least one predefined dual-mode function.

17. A method as set forth in claim 1, wherein subsequent to the performance of the step of initializing, steps are performed by the mobile station of:

executing a Scan Dedicated Control Channels task and tuning to a strongest dedicated control channel;

receiving a first Overhead Message Train (OMT) including a first System Parameter Overhead Message (SPOM), from the strongest dedicated control channel;

storing a System Identification (SID) from the first SPOM;

executing a Scan Paging Channels task and tuning to a strongest paging channel;

receiving a second OMT from the strongest paging channel, the second OMT including a second SPOM;

comparing a SID from the second SPOM to the stored SID; and if they are equal,

entering an Idle task; and if they are not equal,

re-executing the Scan Dedicated Control Channels task.

18. A method as set forth in claim 17, wherein if the Idle task is entered, steps are performed by the mobile station of:

determining if a SID from an SPOM of a received OMT is equal to the stored SID; and if they are equal,

updating parameters stored in the memory using information contained in the SPOM in accordance with a Response to Overhead Information task;

determining (a) whether information specifying the at least one protocol supported by the mobile station was last transmitted by the mobile station to a base station identified by the stored SID, and (b) whether a status of a variable Update Protocol Capability Identifier (UPCID) stored in the memory is enabled; and if (a) and (b) are true,

disabling the status of the variable UPCID; and

entering a System Access Task with a registration indication.

19. A method as set forth in claim 18, wherein if the SID from the SPOM is not equal to the stored SID, a step is performed of re-executing the Scan Dedicated Control Channels task.

20. A method as set forth in claim 18, wherein if at least one of (a) and (b) is not true, steps are performed by the mobile station of:

determining whether an Access Type Parameters Global Action Message (ATPGAM) was included in the OMT, the ATPGAM specifying the first information; and if it is determined that the ATPGAM was included in the received OMT, the mobile station responds by performing the steps of:

storing a value of a busy-idle status (BIS) field from the received OMT;

storing, in the memory, the first information specifying the at least one protocol supported by the base station;

determining (c) whether the first information indicates that the base station supports a predetermined core analog roaming protocol, and (d) whether the information specifying the at least one protocol supported by the mobile station was last transmitted by the mobile station to a different base station than that identified by the SID from the received OMT; and if (c) and (d) are true,

enabling the status of the variable UPCID;

setting the variable PCSID.sub.s equal to the value of the SID from the received OMT; and

entering a System Access Task with a registration indication.

21. A method as set forth in claim 20, wherein if at least one of (c) and (d) is not true, then the mobile station responds by performing the step of:

responding to messages in the received OMT in accordance with a Response to Overhead Information task.

22. A method as set forth in claim 1, and wherein the mobile station further performs the steps of:

monitoring mobile station control messages for at least one of page responses, orders, a user-initiated call, and a non-autonomous registration indication; and responding to detected ones of these messages by executing a Page Match task, an Order task, a Call Initiation task, and a Non-Autonomous Registration Initiation task, respectively;

executing a System Access task;

scanning a set of access control channels and tuning to a strongest access channel in accordance with a Scan Access Channels task;

executing a Retrieve Access Attempts Parameters task and determining whether the mobile station shall receive an Overhead Message Train (OMT); and if the mobile station shall receive the OMT,

receiving the the OMT, including a System Identification (SID);

determining whether an Access Type Parameters Global Action Message (ATPGAM) is included in the OMT, the ATPGAM specifying the first information; and if it is determined that the ATPGAM is included in the OMT, the mobile station responds by performing the steps of:

storing a value of a busy-idle status (BIS) field from the OMT;

determining (e) whether the first information from the OMT indicates that the base station that transmitted the OMT supports a predetermined core analog roaming protocol, and if (e) is true,

storing, in the memory, the first information from the OMT;

determining (f) whether the information specifying the at least one protocol supported by the mobile station was last transmitted by the mobile station to a different base station than that which transmitted the OMT, and if (f) is true,

enabling the status of a variable Update Protocol Capability Identifier (UPCID);

setting the variable PCSID.sub.s equal to the value of the SID; and

executing a Seize Reverse Control Channel task and determining if the reverse control channel is idle, and if it is determined that the reverse control channel is idle,

performing the step of transmitting the second information from the mobile station to the base station.

23. A method as set forth in claim 20, wherein the predetermined core analog roaming protocol includes standard EIA/TIA-553-A or later revisions thereof.

24. A method as set forth in claim 22, wherein the predetermined core analog roaming protocol includes standard EIA/TIA-553-A or later revisions thereof.

25. A cellular telecommunications system, comprising:

at least one base station;

at least one mobile station capable of bi-directional wireless communications with said base station, said mobile station comprising a memory for storing variables comprised of a Protocol Capability System Id (PCSID.sub.s), a Base Station Protocol Capability (BSPC.sub.s), and a Base Station Core Analog Roaming Protocol (BSCARP.sub.s); and

first control means coupled to said base station and second control means coupled to said mobile station for exchanging protocol support information therebetween, said first control means for transmitting first information from the base station over a first analog control channel, the first information specifying at least one protocol supported by the base station, and said second control means being responsive to receiving the transmitted first information for transmitting second information from the mobile station to the base station over a second analog control channel, the second information specifying at least one protocol supported by the mobile station; wherein

said mobile station is responsive to detecting a power-on condition for initializing values of said variables PCSID.sub.s, BSPC.sub.s, and BSCARP.sub.s that are stored in said memory.

26. A system as set forth in claim 25, wherein the at least one protocol supported by the base station includes at least one of a predefined air-interface protocol and a predefined core analog roaming protocol supported by the base station.

27. A system as set forth in claim 25, wherein the at least one protocol supported by the mobile station includes at least one of a predefined air-interface protocol and a predefined core analog roaming protocol supported by the mobile station.

28. A system as set forth in claim 25, wherein the second information also specifies function capability features that are supported by the mobile station.

29. A system as set forth in claim 25, wherein the second information also specifies function capability features that are not supported by the mobile station.

30. A radiotelephone, comprising:

an RF transceiver for conducting bidirectional wireless communications with a base station;

a memory for storing variables comprised of a Protocol Capability System Id (PCSID.sub.s), a Base Station Protocol Capability (BSPC.sub.s), and a Base Station Core Analog Roaming Protocol (BSCARP.sub.s); and

a controller coupled to said transceiver and to said memory for exchanging protocol support information with said base station via said RF transceiver, said RF transceiver receiving first information from said base station over a first analog control channel, said first information specifying at least one protocol supported by said base station, and said controller being responsive to receiving said first information for transmitting second information to said base station through said transceiver over a second analog control channel, said second information specifying at least one protocol supported by said radiotelephone; wherein

said radiotelephone is responsive to detecting a power-on condition of said radiotelephone for initializing values of said variables PCSID.sub.s, BSPC.sub.s, and BSCARP.sub.s that are stored in said memory.

31. A radiotelephone as in claim 30, wherein said at least one protocol supported by said base station includes at least one of a predefined air-interface protocol and a predefined core analog roaming protocol supported by said base station.

32. A radiotelephone as in claim 30, wherein said at least one protocol supported by said radiotelephone includes at least one of a predefined air-interface protocol and a predefined core analog roaming protocol supported by said radiotelephone.

33. A radiotelephone as set forth in claim 30, wherein said second information also specifies function capability features that are supported by said radiotelephone.

34. A radiotelephone as set forth in claim 30, wherein said second information also specifies function capability features that are not supported by said radiotelephone.

FIELD OF THE INVENTION

This invention relates generally to cellular telephones and, in particular, to mobile radiotelephones, also referred to herein as mobile stations, that exchange protocol information with a cellular system.

BACKGROUND OF THE INVENTION

In U.S. Pat. No. 5,020,091 there is described a cellular telephone communications system that includes multiple cells covering a geographical area, such as a metropolitan area. To the base station of each cell a number of frequencies are assigned, with some of the assigned frequencies being specified as control channels used for reciprocal identification between the telephones and the system. The location of the dedicated control channels in the cell's frequency spectrum identifies the type of cellular system, A or B (see, for example, EIA/TIA-553). A metropolitan area typically has one of each type of system.

In a cellular system of most interest to this invention the channel from a base station to the mobile station is referred to as the forward channel, i.e., the forward control channel and the forward voice channel. The channel from the mobile station to the base station is referred to as the reverse channel, i.e., the reverse control channel and the reverse voice channel.

Base stations can transmit various messages over the forward control channel including, by example, mobile station control messages, overhead messages (e.g., Overhead Message Trains (OMTs)), and control-filler messages. Mobile station control messages are transmitted by a base station when paging or sending orders to a mobile station (see, e.g., EIA/TIA-553 Sec. 3.6.2.2 and Sec. 3.6.2.3). Overhead Message Trains are frequently transmitted by base stations. The OMT includes a System Parameter Overhead Message (SPOM), and may also include one or more Global Action Overhead Messages (GAOMs). The SPOM always contains System Identification (SID) information. The SID is unique for each cellular system. The use of the SID enables the cellular phone to determine whether it is using its home system or whether it is roaming. According to current standards (e.g., EIA/TIA-553), the SPOM is transmitted every 800.+-.300 ms, and the GAOMs are transmitted on an as needed basis.

Also according to current standards (e.g., EIA/TIA-553-A), GAOMs can include a Rescan Global Action Message (RGAM), a Registration Increment Global Action Message (RIGAM), a Location Area Global Action Message (LAGAM), a New Access Channel Set Global Action Message (NACSGAM), an Overload Control Global Action Message (OCGAM), an Access Type Parameters Global Action Message (ATPGAM), and Access Attempt Parameters Global Action Message (AAPGAM), a Random Challenge A Global Action Message (RCAGAM), a Random Challenge B Global Action Message (RCBGAM), a Local Control 1 Message (LC1M), and a Local Control 2 Message (LC2M). Exemplary formats of these messages, as in accordance with EIA/TIA-553-A, are shown in FIGS. 5a-5k, respectively.

A base station transmits OMTs to a mobile station in order to, by example, support the mobile station when it is executing the Initialization Task (see, e.g., EIA/TIA-553 Sec. 3.6.1 and Sec. 2.6.1), control the mobile station while it is monitoring a control channel (see, e.g., EIA/TIA-553 Sec. 3.6.2.1), and to support system access by the mobile station (see, e.g., EIA/TIA-553 Sec. 3.6.3.1).

To support system access by the mobile station, the base station transmits various messages in the OMT over the forward control channel (see, e.g., EIA/TIA-553-A Sec. 3.6.3.1). A first message is the Digital Color Code (DCC) message, which, after being transmitted from the base station to the mobile station, is used by the mobile station to identify to the base station which base station transmitter the mobile station is receiving. A second message includes the Control Mobile Attenuation Code (CMAC), which is transmitted from the base station in a control-filler message if the mobile station needs to adjust its transmitter power level before accessing the system on a reverse control channel. A third message includes the Wait-For Overhead Message (WFOM), which specifies whether or not the mobile station must wait to receive an OMT before accessing the system on a reverse control channel. Another message includes the Overload Control (OLC) message, which is appended to the SPOM if the mobile station must not access the cellular system for originations on the reverse control channel. Another message includes the Access Attempts Parameters Message (AAPM), which is appended to the SPOM to indicate that default values must not be used for a number of seizure attempts or the limit on the number of busy occurrences for the mobile station accessing the reverse control channel. A further message is the Access Type Parameters Global Action Message (ATPGAM). The ATPGAM indicates whether or not the mobile station must check for an idle-to-busy status transition on the reverse control channel when accessing a system.

Although a base station can transmit various types of messages to a mobile station over the forward control channel, current standards (e.g., EIA/TIA-533, EIA/TIA-553-A, IS-91, IS-95, and IS-136) for the analog mode do not include protocols for enabling the base station to notify the mobile station of the air-interface protocol version (e.g., AMPS) and the core analog roaming protocol version supported by the base station. By example, as can be seen in view of FIGS. 5a-5k, none of the GAOMs of EIA/TIA-553-A include data fields which specify air-interface protocol or core analog roaming standard information. As a result, if the mobile station is not able to be notified of the air-interface protocol version and the core analog roaming standard supported by the base station, the mobile station may originate messages that are not capable of being processed by the base station.

Current standards (e.g., EIA/TIA-533, EIA/TIA-553-A, IS-91, IS-95, and IS-136) also do not include protocols for enabling the mobile station operating in the analog mode to notify the base station of the air-interface protocol version, the core analog roaming protocol version, and the capability features (e.g., Call Waiting, Calling Line Identification) supported/not supported by the mobile station. By example, according to current standards (e.g., EIA/TIA 553), the types of messages that may be transmitted by a mobile station over the reverse control channel can include a page response message, an origination message, an order confirmation message, and an order message. The messages may consist of the words shown in FIGS. 6a-6j. FIG. 6a shows data fields of an Abbreviated Address Word (Word A) , and FIG. 6b shows data fields of an Extended Address Word (Word B). FIG. 6c shows data fields of a Serial Number Word (Word C). FIG. 6d shows data fields of Second Word of the Called-Address (Word E), and FIG. 6e shows data fields of an Authentication Word (Word C). A Unique Challenge Order Confirmation Word (Word C) is shown in FIG. 6f, and a Base Station Challenge Word (Word C) is shown in FIG. 6g. FIG. 6h shows data fields of a First Word of the Called Address (Word D), and FIG. 6i shows data fields of a Third Word of the Called Address (Word F) Also, FIG. 6j shows data fields of a Fourth Word of the Called-Address (Word G). As can be appreciated, none of these words include data fields which indicate the version of the air-interface protocol version supported by the mobile station, the core analog roaming protocol version supported by the mobile station, or the capability features supported/not supported by the mobile station.

Being that capability feature information and air-interface/core analog roaming protocol version information cannot be provided from a mobile station to a base station operating in the analog mode in accordance with conventional standards, cellular systems cannot differentiate between mobile stations that can process certain messages and those that cannot process these messages. Also, certain information such as, for example, Calling Line/Number Identification can be delivered by the base station to the mobile station using specific protocols, such as, for example, the Alert with information protocol or the Extended Protocol Calling Line Identification protocol. Unfortunately, however, since current standards for the analog mode do not enable the mobile station to notify the base station of the capability features supported by the mobile station, the base station has no way of determining the correct protocol to use in order to deliver the Calling Line/Number Identification to the mobile station. If the base station transmits a message to the mobile station, and the mobile station does not have the capability of processing the message, undesirable consequences can result. For example, the mobile station may not execute the message and/or a call may not be delivered to a user.

As is depicted in FIG. 1, a typical cellular network is divided into a number of regions (e.g., SID1-SID5) each having contiguous radio cells (shown nominally as hexagons). One region or SID may also include one or more paging areas, each encompassing one or more radio cells.

OBJECT OF THE INVENTION

It is an object of this invention to provide a method for exchanging air-interface protocol version information and core analog roaming protocol version information between a mobile station and a cellular system.

It is another object of this invention to provide a method for enabling a mobile station to notify a base station of capability features that are supported/not supported by the mobile station.

SUMMARY OF THE INVENTION

The foregoing and other problems are overcome and the objects of the invention are realized by a method for exchanging protocol support information between a base station and a mobile station. The method includes a first step of transmitting from a base station information specifying at least one protocol supported by the base station. The information includes an ATPGAM having a format that is in accordance with the invention. Preferably, the ATPGAM includes information specifying a predefined air-interface protocol supported by the base station such as, by example, EIA/TIA 553 and earlier revisions, IS-54A, EIA/TIA 627, IS-54B (dual-mode), IS-95a (dual-mode), IS-136a (dual-mode), EIA/TIA 691 (dual-mode), or later revisions of these standards. Also, the ATPGAM preferably includes information specifying a predefined core analog roaming protocol supported by the base station such as, by example, EIA/TIA-553 and earlier revisions, EIA/TIA-533 A, or later revisions of these standards.

A next step includes receiving at the mobile station the information transmitted by the base station. In response to receiving this information, the mobile station transmits a Protocol Capability Registration Message (PCRM), which specifies at least one protocol supported by the mobile station, to the base station. In accordance with a preferred embodiment of the invention, the PCRM specifies the air-interface protocol and the core analog roaming protocol supported by the mobile station. These protocols may include, for example, any of those mentioned above, or later revisions thereof. Also in the preferred embodiment of the invention, the PCRM includes information specifying capability features that are supported or not supported by the mobile station. By example, depending on the particular capability features supported by the mobile station, the PCRM may indicate that the mobile station supports or does not support core analog features such as Calling Line Identification (CLI), Call Waiting (CWT), Message Waiting Notification (MWN), and splash ringing via abbreviated alert. Also by example, the PCRM may indicate that the mobile station supports or does not support various dual-mode functions.

In accordance with a preferred embodiment of the invention, the mobile station does not respond to the ATPGAM received from the base station if the mobile station determines that a PCRM was previously transmitted from the mobile station to the base station in response to the mobile station previously receiving an ATPGAM from the base station.

BRIEF DESCRIPTION OF THE DRAWINGS

The above set forth and other features of the invention are made more apparent in the ensuing Detailed Description of the Invention when read in conjunction with the attached Drawings, wherein:

FIG. 1 illustrates a portion of a conventional cellular service area comprised of multiple SIDs, multiple paging areas within a SID, and multiple cells within a paging area;

FIG. 2 is a block diagram of a radio telephone subscriber unit, or mobile station, that is constructed and operated in accordance with this invention;

FIG. 3 is a block diagram of a cellular system base station that is constructed and operated in accordance with this invention;

FIG. 4a illustrates an Overhead Message Train (OMT) being transmitted from a base station to a mobile station;

FIG. 4b illustrates a Protocol Capability Registration Message (PCRM) being transmitted from a mobile station to a base station;

FIGS. 5a-5k show formats of Global Action Overhead Messages (GAOMs) according to the prior art;

FIGS. 6a-6j illustrate formats of reverse control channel (RECC) words in accordance with the prior art;

FIGS. 7a-7c illustrates a logic flow diagram that illustrates a method of this invention;

FIG. 7 illustrates the relationship between FIGS. 7a-7c;

FIG. 8a is a logic flow diagram that illustrates in greater detail the function of the Block J of FIG. 7c;

FIG. 8b is a logic flow diagram that illustrates in greater detail the function of the Block O of FIG. 7c;

FIG. 9a illustrates the format of an Access Type Parameters Global Action Message (ATPGAM) in accordance with the invention;

FIGS. 9b-9e illustrate words of a Protocol Capability Registration Message (PCRM) in accordance with the invention;

FIG. 10a illustrates the format of an exemplary ATPGAM in accordance with the invention;

FIGS. 10b-10e illustrate the format of an exemplary PCRM in accordance with the invention; and

FIGS. 11a-11e illustrate examples of messages being transmitted between a base station and a mobile station in accordance with a method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIG. 3 for illustrating a base station 26 that is suitable for practicing this invention. The base station 26 includes an antenna 28 for transmitting signals to and for receiving signals from a mobile station. To this end the base station includes a transmitter 30, a receiver 32, and a controller 34 that provides signals to and receives signals from the transmitter 30 and receiver 32, respectively. These signals include signalling information in accordance with the air interface of the cellular system (e.g., EIA/TIA-553 or IS-91).

The base station 26 also includes a memory 36 that includes a sub-memory 36a. Within the memory 36 and sub-memory 36a are stored a plurality of constants and variables that are used by the controller 18 during the operation of the base station. For example, the memory 36 stores the value of one or more SIDs, including the base station's home SID. The memory 36 also stores message information used in overhead messages. By example, the memory 36 stores Global Action Overhead Message (GAOM) information. This information includes an Action Type Parameters Global Action Message (ATPGAM) which has been modified in accordance with the invention to include information in addition to that provided in the prior art ATPGAM of FIG. 5f (the ATPGAM of FIG. 5f includes data fields labelled "T1T2", "DCC", "ACT", "BIS", "END", "OHD", and "P"). The format and data fields of the ATPGAM in accordance with a presently preferred embodiment of the invention are shown in Table 1 and FIG. 9a. The number of bits per data field is also shown in Table 1 and FIG. 9a. As can be seen in view of Table 1 and FIG. 9a, in addition to the data fields labelled "T1T2", "DCC",