MXPA97005787A - Method and apparatus for paging a concentrated deubscriptor system for a localinalambr cycle - Google Patents

Abstract

The present invention relates to a method for generating paging messages in a code division multiple access cellular telephone system comprising the steps of: a) tracking a state of a concentrated subscriber system for a subscriber unit, and b) generating a paging message addressed to said subscriber unit in a first way if said state of concentrated subscriber system is positive, and in a second way if said state of concentrated subscriber system is negative.

Description

METHOD AND APPARATUS FOR PAGING A SUBSCRIBER SYSTEM CONCENTRATE FOR A WIRELESS LOCAL CYCLE BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to wireless telephone systems. More particularly, the present invention relates to a method and apparatus for paging a concentrated subscriber system for a wireless local loop that allows simplified construction of the concentrated subscriber system while maintaining maximum compatibility with prior cellular cellular telephone systems. II. Description of the Related Art Wired or wired-based telephone systems are the traditional method for providing non-mobile telephone service. Telephone systems based on wiring are very suitable for this task since they provide high quality connections at a low operating cost and can accommodate an increased demand for telephone service by introducing new telephone cables in the existing network. A disadvantage of telephone systems based on wiring is the substantial infrastructure and capital necessary for its implementation. These requirements can make telephone systems based on non-economic wiring in areas that are remote or less populated, or in less developed areas where the required capital is not available. The result is that these less populated and remote areas often lack adequate telephone service which is detrimental to the economic well-being of the people living in those areas. Also, the time needed to put the required infrastructure in place makes telephone systems based on wiring less desirable in areas where the new telephone service must be provided quickly. Wireless cellular telephone systems require substantially less capital and infrastructure than telephone systems based on cabling and therefore provide a possible alternative to providing basic telephone service. However, the degree to which cellular telephone systems can provide basic telephone service is limited by its higher operating cost compared to the telephone system based on wiring which translates into a higher cost of use for the subscriber of the cellular telephone system. . This higher cost of use limits the number of subscribers who can afford to use a cellular telephone system as their basic telephone service provider within a given area and therefore reduces the number of markets in which the use of cellular telephone systems is economical. A cellular telephone system that provides a simple telephone service at a reduced cost compared to previous cellular telephone systems is disclosed in Co-pending US Patent Application No. 08 / 384,291 entitled "Concentrated Subscriber System for Wireless Local Cycle" filed concurrently with the filed on January 31, 1995 and assigned to the assignee of the present invention. The concentrated subscriber system described in that application includes a set of subscriber units that share a control and interface system which in the preferred embodiment incorporate digital code division multiple access (CDMA) technology due to its high amplitude efficiency. band and its high quality communication capability. Such a system reduces the cost of cellular telephone service incurred by each mobile telephone subscriber by spreading the cost of control and the interface system over a greater number of subscribers. This increases the number of markets in which it is economical to use cellular telephone systems as a basic telephone service provider and therefore increases total access to telephone service.

Many cell phone systems, including those that use the preferred CDMA technology, page or "call" the various subscriber units that are part of the cellular telephone system that use a unique paging method for each subscriber unit or subset of subscriber units that are part of the cellular phone system. This is done so that the page messages can be directed to a single or a subset of the total number of subscriber units, thereby simplifying the monitoring process per page for each subscriber unit. However, in the case of the concentrated subscriber system, the use of multiple paging methods for paging makes the control and interface system described more complex. This is because the control and interface system must be able to interact according to multiple different paging methods in order to monitor paging messages addressed to any of the multiple subscriber units that are part of the concentrated subscriber system. However, greater complexity is contrary to the purpose of the concentrated subscriber system, which is to provide basic cellular telephone service at a reduced cost. Accordingly, the use of the standard paging method of a subscriber unit in combination with a cellular telephone system of a concentrated subscriber system is undesirable. SUMMARY OF THE INVENTION Based on the foregoing, a method and apparatus for paging a concentrated subscriber system for a wireless local cycle within a cellular telephone system is described. Within a mobile telephone switching office (MTSO) a visitor location record is generated in which a subscriber unit identification number (SUIN) for each subscriber unit re-fused within the coverage area is stored together with the number corresponding telephone code, the latest cell site identification code and concentrated subscriber system status information (CSS). The SUIN may correspond to the electronic serial number (ESN), mobile identification number (MIN), or other unique identification code assigned to each subscribing unit. When a call is received addressed to a subscriber unit having a particular telephone number, the corresponding SUIN, CSS status information, and the information of the last cellular site of that subscriber unit are determined, using the visitor's location directory. In response to this determination, a paging code is calculated in various ways depending on the CSS status information resulting from the subscribing unit being paged. If the subscriber unit being addressed is part of a CSS, the paging code used to generate the paging message is calculated in a first way in such a way that it is the same for each subscriber unit within a particular CSS. If the CSS status information indicates that the subscribing unit being paged is not part of a CSS, the paging code is calculated in a second form in such a way that it is different for each subscribing unit. A set of paging parameters is then calculated using the paging code which in the preferred embodiment includes a CDMA channel, a paging channel, and a paging slot. The page message is then transmitted in accordance with those paging parameters. In the preferred embodiment, the page message generation process using the paging parameters is the same as that of the cellular system of the prior art in order to maintain maximum compatibility with those systems of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS The features, objects, and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters are identified correspondingly to through them and where: Figure 1 is a diagram of a cellular telephone system consistent with the use of CDMA modulation and radio techniques; Figure 2 is a diagram of a cellular telephone system configured in accordance with an eiment of the invention; Figure 3 is a block diagram of the mobile telephone switching office configured in accordance with one eiment of the invention, and Figure 4 is a block diagram of a base station transceiver configured in accordance with the described eiment of the invention. .

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES A method and apparatus for paging a subscriber unit within a concentrated subscriber system for a wireless local cycle is described. In the following description, various variables, procedures, and facilities are described in detail. In particular, the invention is described in the context of a code division multiple access cellular telephone system (CDMA) that incorporaa paging method that has paging parameters that include a CDMA channel, a paging channel and a slot. of paging. For an expert in the field, it will be apparent that these details and specifications are not required to practice the present invention and that the present invention can be implemented within alternative cellular telephone systems or other means of communication based on radio waves including base systems. to satelli In other cases, various well-known structures and systems are provided in block form. This is done in order to avoid unnecessary obscuration of the disclosure of the present invention.

Figure 1 is an illustration of a cellular telephone system configured in a manner consistent with the use of radio wave modulation techniques of Multiple Access by Code Division (CDMA). One implementation for such a CDMA cellular telephone system is described in U.S. Patent 4,901,307 (307) entitled "Broadcast Spectrum Multiple Access Communication System Utilizing a Satellite or Repeater Terrestre "and 5,103,459 (59) entitled" System and Method for Generating Signal Waveforms in a System CDMA Cell Phone "both assigned to the assignee of the present invention, as well as in the IS-95 specification of the Telecommunications Industry Association (2001 Pennsylvania Avenue, Suite 800, Washington, DC 20006) entitled" Station Compatibility Standard Mobile-Base Station for a Broadband Dual-Mode Broadband Spectrum Cell System (IS-95) Radio Frequency (RF) signals generated in response to both incoming and outgoing telephone calls according to the aforementioned patents 59 and x307 and the IS-95 specification are exchanged between the subscriber units 10 and 12 and the base station transceivers 14, 16 and 18. Typically, the additional subscriber units also exchange such RF signals, but are not shown to facilitate the The base station transceivers 14, 16 and 18 'communicate in various ways including terrestrial or microwave-based cabling links with an office mobile telephone switching (MTSO) 20 which directs calls to the public switched telephony network (PSTN) 22 and which interacts similarly with other cellular si24. In general, subscriber units 10 and 12 communicate directly each. As described in patents? 459 and? 307 and the IS-95 specification, the "forward link" communication that takes place from the base station transceivers 14, 16 and 18 to the subscriber units 10 and 12 is carried out on various advance CDMA channels - what ¬ each of which occupies 1.23 MHz of radio frequency bandwidth. Each of these forward CDMA channels is divided into several additional channels that are separated and distinguished through the use of unique pseudo-random broadcast codes that are applied to the data that is being transmitted. For the channels carrying signals to be received by both subscriber units 10 and 12, a predetermined broadcast code is used, which is known for each communication unit including both subscriber units 10 and 12. For the channels that carry data proposed only for one of the subscriber units 10 or 12, a broadcast code known only to the particular communication unit is used, which is generally determined as a function of an electronic serial number (ESN) of thirty-two bits, unique, stored in each subscribing unit. In addition to the ESN each subscriber unit may also be associated with a mobile identification number (MIN) which in the preferred embodiment is also 32 bits, as well as additional, unique identification codes.

The various channels within a given forward CDMA channel include a set of data channels, a synchronization channel, a pilot channel, and a set of paging channels, all transmitted from the base station transceivers 14, 16. and 18 to the subscriber units 10 and 12. The pilot channel carries a pilot signal which is a slight phase shift of regularly repeated pattern for each cell site in a local area that is received by each subscriber unit including subscriber units 10 and 12 The pilot signal allows the subscriber units 10 and 12 to identify and synchronize with the various base station transceivers that are within the range of their communication capability. The synchronization channel carries additional synchronization information to be used by both subscriber units 10 and 12. The set of data channels carries the data associated with the various communication sessions (usually telephone calls) and is directed to a specific subscriber unit. The paging channels are used by the base station transceivers to notify a particular subscriber unit that a request has been received to communicate.

As also described in patents 59 and? 307 and the IS-95 specification, the protocol for paging a subscriber unit is defined in order to evenly distribute the background noise and to reduce the power consumption. This is done by dividing each paging channel into a set of paging "slots" or time windows during which the paging signals directed to any of the subscriber units 10 and 12 can be generated, and by assigning a CDMA channel. in particular, a paging channel and a paging slot to each subscriber unit in a uniformly distributed manner. This assignment is carried out through the use of a key calculation function applied to the ESN of each subscriber unit under the established protocol although other unique numbers could be used. The key calculation function produces a value that corresponds to a particular set of paging parameters that include a CDMA channel, paging channel, and paging slot. The subscriber units are then configured to "listen" for a paging message on the corresponding CDMA channel and the paging channel during the corresponding paging slot. Since the hearing of a page requires a certain amount of energy, limiting the time in which the subscriber unit performs the listening function for a particular paging slot reduces the total energy consumption of that subscriber unit and consequently the life of any battery or other energy storage system used by that subscriber unit is increased. In general, the page message itself will contain the ESN of the subscriber unit that is being paged in coded form so that it can identify itself when the page is received, although other identification codes could theoretically be used. Figure 2 is a block diagram of a cellular telephone system configured in accordance with an embodiment of the present invention. The base station transceiver 102 transmits and receives modulated radio waves according to CDMA broadcast spectrum techniques described in the above-referenced patents 59 and? 307 and the IS-95 specification to and from subscriber units 100 and 112. In a manner In addition, the base station transceiver 102 communicates with the mobile telephone switching office (MTSO) 104 in any of a variety of ways including microwave link, IT cable or land based connection, or a combination thereof. The MTSO 104 communicates with the public telephone switching network (PSTN) 106 allowing various communication sessions or telephone calls to be distributed between the base station transceiver 102, the base station transceiver 110, and other cellular sites 108. Both subscriber units 100 and 112 have a unique thirty-two-bit electronic serial number (ESN) as well as other unique identification codes as described above.

The base station transceiver 110 communicates with the MTSO 104 in a manner similar to the base station transceiver 102 and communicates with the subscriber unit 112 and the concentrated subscriber system (CSS) 113 through modulated radio waves in accordance with the patents referred to above 59 and 307 and the IS-95 specification. Within the CSS 113 the subscriber units 116 (1) to (50) are coupled to the CSS controller 114 which carries out the interface function with the base station transceiver 110. To the subscriber units 116 (1) a (50) each is also assigned a unique ESN and can be used in a manner similar to a standard telephone to initiate and receive telephone calls. Although the CSS controller 114 is shown coupled directly to the subscriber units 116, alternative methods for exchanging information are contemplated which include a simplified form of communication based on radio waves. The configuration and operation of the CSS controller 114 is described in greater detail in the copending US patent application, previously mentioned, series no. 08 / 384,291 entitled "Concentrated subscriber system for a Wireless Local Cycle". During operation, the base station transceiver 110 receives requests to communicate with the subscriber unit 112 and the subscriber units 116 as well as with other subscriber units not shown to facilitate the drawing, coming from the MTSO 104. In response to each demand, the transceiver of base station 110 generates a paging message addressed to the corresponding cellular communication system, determining a CDMA channel, a paging channel, and a paging slot using a paging code provided in the request. The paging code is calculated in one of two ways depending on whether the subscribing unit that is being paged is part of a concentrated subscriber system. If the communication unit being paged is not part of a CSS, the paging code is set to a subscriber unit identification number (SUIN) associated with the subscriber unit being paged, which in the preferred embodiment is the ESN of that subscriber unit, although any other unique identification code associated with the subscriber unit could be used as the SUIN including the MIN, or the SUIN could be an additional unique code associated with each subscriber unit 116. If the subscribing unit that is being paged is a subscriber unit 116 and consequently is part of a CSS, the paging code is calculated in an alternative manner which will cause the page message to be generated using the same CDMA channel, paging channel and paging slot for each subscriber unit 116. Figure 3 is a block diagram of the MTSO 104 when configured in accordance with the mode of scrit The processor subsystem 129 receives and transmits data to and from the PSTN 106 of Figure 2, as well as receives and transmits data to and from base station transceivers 102 and 110 also of Figure 2. The memory subsystem 130 is coupled to the processor subsystem 129 and provides data storage functionality. In the preferred embodiment, the processor subsystem 129 incorporates the use of at least one microprocessor and the memory subsystem 130 incorporates the use of any integrated circuit, hard disk, optical, or magnetic memory, or a combination thereof. Various circuits and additional systems are included within the MTSO which include interface systems located between the processor subsystem 129 and the PSTN 106 and the base station transceivers 102 and 110 which are well known in the art, but are not shown to facilitate drawing and in order not to unnecessarily obscure the disclosure of the present invention. During the operation, communication requests are received that include a telephone number of the subscriber unit with which communication is being requested, by the processor subsystem 129. The processor subsystem 129 conducts a search with the provided telephone number, using a visitor location register (VLR) generated and maintained within the memory subsystem 130 by the processor subsystem 129. The VLR is a table containing information extracted from an address location register (HLR) also stored with the memory subsystem 130 containing information for all active ("on") subscriber units that have registered with the MTSO 104. The HLR is a table that contains information associated with all the subscribers that have accounts with the cellular telephone operator of the MTSO 104 and the associated services to which they have subscribed. Although the? ^ LR and the HLR are displayed within the same memory subsystem 130 and controlled by the processor subsystem 129 both of which are located within the MTSO 104, it is contemplated that the two tables can be maintained separately by different systems and in different places. In the preferred embodiment, the VLR table contains a subscriber unit identification number (SUIN), the telephone number or numbers, the CSS status, and the last base station identification number (BID) of each subscriber unit that is has been registered when activated and within the coverage area of the MTSO 104. The SUIN is usually the ESN of the unit - subscriber although other unique identification codes may also be substituted. This information is constantly updated as the subscriber units enter and leave the coverage area or are activated and deactivated. The state of CSS is stored in different ways in different embodiments of the invention. In one mode, the CSS state includes a CSS status bit (CSB) which indicates whether a particular subscriber unit is part of a CSS and is therefore a subscriber unit 116. Generally, a "one" indicates a positive state and a "zero" indicates a negative state although this, of course, could change. In an alternative embodiment, the CSS status may be indicated by a concentrated subscriber system identification code (CSSIC) stored within the HLR and the VLR instead of or in addition to this CSS status bit. The CSSIC is a number that indicates the particular CSS with which the subscriber unit is associated. A CSSIC of zero generally indicates a negative CSS status, however, other values can easily be used to indicate a negative CSS state. The preferred length for the CSSIC is thirty-two bits. Table I lists a set of exemplary entries stored in the VLR.

TABLE I SUIN Number CSB CSSIC Last Telephone BID A16F 2051 619,555.1000 0 0000 0000 04F1 A16F 4051 619,555.1221 0 0000 0000 0539 A156 7151 619.555.1800 1 0751 64F3 2CF1 B34A 1F35 619.555.1801 1 2C41 0551 03A7 946D 3B74 619.555.1805 1 04A5 2CF1 57F6 3578 2041 619,555.1900 1 6493 9DA7 B4F1 A16F 2051 619.555.1903 1 87F6 57F9 14A1 All numbers are displayed in hexagonal format except the telephone number which is displayed in decimal format for ease of understanding although in reality it can be stored in binary format like the other values. After the search is carried out, a paging demand is generated d on the resulting SUIN and the CSS status information by the processor system 129 and transmitted to the station transceiver associated with the last BID in which it is stored. located the subscriber unit. Generally, the demand for paging is also transmitted to other station transceivers located in adjacent cells in the event that the subscriber unit has moved, a practice well known in the art. In the preferred embodiment, a page request includes the MIN of the subscriber unit being paged and a paging code, which is also referred to as a paging ESN. Another identification number may be included in the page request instead of or in addition to the MIN that includes the ESN in other embodiments of the invention. The paging code is calculated in a variety of ways depending on the CSS status of the subscribing unit that is being paged. If the CSS status information is negative indicating that the subscribing unit that is being paged is not part of a CSS, the paging code is established in the SUIN, which as noted above is the ESN of the subscribing unit that is being paged in the preferred mode. This process is consistent with the process of calculation of paging parameters of the IS-95 standard. If the CSS status information is positive, indicating that the subscribing unit that is being paged is part of a CSS, the paging code is set to an alternative number that simplifies the page monitoring process of the CSS controller 114 of the Figure 2. Although in the described embodiment the paging code calculation process takes place with the MTSO 104 it is also contemplated that it could take place within the station transceiver to which the page demand is transmitted. The paging code establishes different values in different embodiments of the invention. In a first embodiment of the invention, the paging code is set to a predetermined number when the CSS state of the subscriber unit being paged is positive. In a second embodiment of the invention, a positive CSS status results in the paging code being established in the CSSIC of the CSS in which the modified subscriber unit that is being paged is located. In a third embodiment of the invention, a positive CSS state results in a paging code that is set to a number that is calculated by masking a portion of the SUIN of the subscriber unit that is being paged and by applying the calculation function of normal key to this masked SUIN. Again, as noted above in the preferred embodiment of the invention, the SUIN is the ESN of the subscriber unit that is being paged although other identification numbers may also be used. In the third embodiment each subscriber unit associated with a given CSS is assigned a SUIN with an identical set of twenty high-order bits, although other identical bit quantities located anywhere within the SUIN are contemplated and are consistent with the invention. The twelve low order bits are then masked preferably with all zeros, and the paging code is set in this masked number.

Figure 4 is a block diagram illustrating the configuration of the various systems used to build the base station transceiver (BTS) 110 according to the described embodiment of the invention. The RF transceiver 156 generates radio frequency signals transmitted from the antenna 158 in response to the information generated by the base station processor 152 which in the preferred embodiment is a microprocessor. The base station processor 152 stores and retrieves data from the memory subsystem 150 in order to generate this information. The MTSO interface 154 interacts with the MTSO 104 of Figure 2 and receives and transmits information to and from the base station processor 152 that includes demands for paging a subscriber unit. In the preferred embodiment, the memory subsystem 150 is comprised of integrated, optical or magnetic circuit memory, or a combination thereof. The base station processor 152 performs various functions that allow the BTS 110 to control telephone calls including the calculation of paging parameters including the CDMA channel, the paging channel, and the paging slot used to send paging messages to the various subscriber units within their coverage area in response to the paging demands received from the MTSO 104.

In general, these paging parameters are calculated by applying a key calculation function for the paging code transmitted by the MTSO 104 with any paging request. In the preferred embodiment, the key calculation function used is that described in the IS-95 specification referred to above in order to keep the system as compatible as possible with the prior art, although the use of other calculation functions is contemplated. key. The effect of generating the paging parameters through the application of a key calculation function for a paging code that is calculated in accordance with the procedures described above is that the concentrated subscriber system can be constructed at a reduced cost and can be operate within a digital cellular telephone system thereby increasing its total utility. This is because in each of the three modalities described, the paging code provided will be the same for each subscriber unit associated with a particular CSS. This causes the same CDMA channels, paging channel and paging slot to be used to page each subscriber unit associated with the CSS, thus simplifying the page monitoring function of the CSS. However, when calculating the paging code according to the prior art, when the subscriber unit being paged is not associated with a CSS, the described system also operates correctly with the subscriber units consistent with the prior art. This allows the same infrastructure to be used to provide both a low cost mobile phone service and a higher cost mobile phone service, thereby increasing the number of subscribers it can serve. The various embodiments of the invention described above, each provide additional benefits. In the first embodiment of the invention, in which the paging code is set to a predetermined value when the CSS state of the subscriber unit being paged is positive, the calculation process is simplified. However, using the same default paging code for each CSS in the first mode causes the associated CDMA channel, the paging channel, and the paging slot to be used significantly more often than others when multiple CSS sites are located within the coverage area of a given base station transceiver. This causes the noise created by the paging messages to be distributed non-uniformly and therefore interferes with the communication of other subscribers within the cellular site coverage area.

This non-uniform distribution is reduced in the second embodiment of the invention described above where the paging code that is established in the CSSIC of the CSS in which the subscribing unit that is being paged is located, is provided in the paging request transmitted to from the MTSO 104. The use of the CSSIC as the paging code will still make use of the same CDMA channel, paging channel and paging slot to page each subscriber unit associated with a given CSS, but will cause different channel to be used of CDMA, paging channel and paging slot for subscriber units that are part of different CSS systems. This will be distributed more evenly to the paging signals that are being generated through a particular area of cellular coverage and therefore it is preferred when it is desirable to reduce such interference. The third embodiment of the invention described above in which the paging code is set to a number calculated by making a portion of the SUIN associated with the subscriber unit being paged, provides benefits similar to the second in which it is distributed in a manner more uniform the generation of the page message through the CDMA channel, paging channels and paging slots available. Additionally, the third mode reduces the amount of information that must be stored within the VLR and HLR generated within the MSC 104 of Figure 2 because the SUIN is used both to identify the subscriber unit and to recalculate the paging code . Additionally, the twelve-bit masking of low order in the third mode for calculating the paging code allows assigning over ten thousand cell units to a particular concentrated subscriber system. This provides enough unique numbers to distinguish ten thousand phones that correspond to about ten base four-digit extensions common in the telecommunications industry. In this way a method and apparatus for paging a concentrated subscriber system for a wireless local cycle is described. Other embodiments of the invention will be apparent to those skilled in the art. The above-described embodiment is provided merely for illustrative purposes and should not be taken as limiting the scope of the invention which is set forth in the following claims.

Claims (30)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the claim described in the following claims is claimed as: 1. A method for generating paging messages in a multiple access cellular teone system by code division that it comprises the steps of: a) tracking a state of a concentrated subscriber system for a subscriber unit; and b) generating a paging message addressed to said subscriber unit in a first way if said state of the concentrated subscriber system is positive, and in a second way if said state of the concentrated subscriber system is negative. The method according to claim 1, characterized in that said step a) comprises the steps of: al) storing a subscriber unit identification number, a teone number, and status information of the concentrated subscriber system associated with said subscriber unit in a visitor location record; and a.2) searching for said subscriber unit identification number and said subscriber system status information concentrated in said visitor location register using said teone number. The method according to claim 2, characterized in that said step b) comprises the steps of: b.l) receiving said subscriber unit identification code and said concentrated subscriber system status information; b.2) examine said concentrated subscriber system status information, b.3) calculate a paging code in a first way if said concentrated subscriber system status information is positive, and in a second way if said information is state of concentrated subscriber system is negative; and b.4) generating said paging message using said paging parameters. The method according to claim 3, characterized in that said step b.3) comprises the step of establishing said paging code equal to a predetermined value if said concentrated subscriber system status information is positive, and said identification code of subscriber unit if said concentrated subscriber system status information is negative. The method according to claim 3, characterized in that step b.3) comprises the step of establishing said paging code equal to a concentrated subscriber system identification code also stored in said visitor location register if said information of The subscriber system status is concentrated positive, and said subscriber unit identification code if said status of the subscriber system is negative. The method according to claim 3, characterized in that step b.3) comprises the steps of: masking a set of bits within said subscriber unit identification code if said concentrated subscriber state information is positive; and establishing said paging code for said subscriber unit identification code. The method according to claim 3, characterized in that step b.2) comprises the step of determining whether a status bit of a concentrated subscriber system is established. The method according to claim 3, characterized in that step b.2) comprises the step of determining whether a concentrated subscriber system identification code that is part of said concentrated subscriber system status information is equal to a first value. The method according to claim 6, characterized in that said set of paging parameters is calculated using said paging code wherein said paging parameters comprise a multiple access channel by code division, a paging channel and a paging slot . The method according to claim 3, characterized in that said paging message includes the subscriber unit identification code of the subscriber unit being paged. 11. An apparatus for generating paging messages in a cellular teone system comprising: means for tracking a state of a concentrated subscriber system for a subscriber unit and for generating a paging code in a first way if said state of the subscriber system is concentrated is positive, and in a second way if said state of concentrated subscriber system is negative; and means for generating a paging message based on said paging code. The apparatus according to claim 11, characterized in that said means for tracking comprises: means for storing an electronic serial number, a telephone number, and status information of the concentrated subscriber system associated with said subscriber unit in a location register of visitor; and means for searching said electronic serial number and said subscriber system status information concentrated in said visitor location register using said telephone number.13. The apparatus according to claim 12, characterized in that step b) comprises: means for receiving said subscriber unit identification code and said concentrated subscriber system status information; means for examining said concentrated subscriber system status information; means for calculating paging parameters in a first way if said concentrated subscriber system status information is positive, and in a second way if said concentrated subscriber status information is negative. The apparatus according to claim 13, characterized in that said calculating means comprise: means for establishing said paging code equal to a predetermined value if said concentrated subscriber system status information is positive, and said subscriber unit identification code if said concentrated subscriber information is negative. The apparatus according to claim 13, characterized in that said calculating means comprise: means for establishing said paging code equal to a concentrated subscriber system identification code also stored in said visitor location register if said status information of The concentrated subscriber system is positive, and said subscriber unit identification code if said state of the concentrated subscriber system is negative. The apparatus according to claim 13, characterized in that said calculating means comprise: means for masking a set of bits within said subscriber unit identification code if said concentrated subscriber state information is positive; and means for establishing said paging code for said subscriber unit identification code. The apparatus according to claim 13, characterized in that said examination means comprise means for determining whether a concentrated subscriber system state bit is established. The apparatus according to claim 13, characterized in that said means of examination comprises means for determining whether a concentrated subscriber system identification code that is part of said concentrated subscriber system status information is equal to a first value. 19. The apparatus according to claim 16, characterized in that said set of values comprises a channel of multiple access by division of code, a paging channel and a paging slot. The apparatus according to claim 13, characterized in that said paging message includes the identification code of the subscriber unit that is being paged. 21. A system for generating paging messages in a code division multiple access cellular telephone system comprising: a telephone switching office, mobile to track a concentrated subscriber system status for a subscriber unit and to generate a message of page addressed to said subscriber unit in a first way if said state of concentrated subscriber system is positive, and in a second way if said state of concentrated subscriber system is negative; and a base station transceiver system for generating said paging message using said paging code. The system according to claim 21, characterized in that said mobile telephone switching office comprises a memory system for storing a subscriber unit identification code, a telephone number, and status information of the concentrated subscriber system associated with said subscriber unit. in a visitor location record; and a processor system for searching said subscriber unit identification code and said subscriber system status information concentrated in said visitor location register using said telephone number. The system according to claim 22, characterized in that said processor system examines said concentrated subscriber system status information, and calculates a paging code in a first way if said concentrated subscriber system status information is positive, and in a second way if said concentrated subscriber status information is negative; a base station transceiver system for generating said paging message using said paging code. 24. The system according to claim 23, characterized in that said processing system calculates said paging code by setting said paging code equal to a predetermined value if said concentrated subscriber system status information is positive, and said identification code. of subscriber unit if said concentrated subscriber information is negative. The system according to claim 23, characterized in that said processor system establishes said paging code in a concentrated subscriber system identification code also stored in said visitor location register if said concentrated subscriber system status information is positive , and in said subscriber unit identification code if said concentrated subscriber information is negative. The system according to claim 23, characterized in that said processor system calculates said paging code by: masking a set of bits within said subscriber unit identification code if said concentrated subscriber state information is positive; and establishing said paging code for said subscriber unit identification code. The system according to claim 23, characterized in that said processor system examines said CSS information when determining whether a concentrated subscriber system state bit is established. The system according to claim 23, characterized in that said processor determines whether a concentrated subscriber system identification code that is part of said concentrated subscriber system status information is equal to a first value. The system according to claim 26, characterized in that said base station transceiver uses said paging code to calculate a set of paging parameters wherein said paging parameters comprise a multiple access channel by code division, a paging channel. and a paging slot. 30. The system according to claim 23, characterized in that said page message includes the identification code of the subscriber unit that is being paged. SUMMARY A method and apparatus for paging a concentrated subscriber system (113) for a wireless local cycle within a cellular telephone system is described. Within a mobile telephone switching office (MTSO) (104) a visitor location register (130) is generated in which a subscriber unit identification number (SUIN) for each subscriber unit registered within the coverage area is stored along with the corresponding telephone number, last cell site, and state information of the concentrated subscriber system (CSS). The SUIN may correspond to the electronic serial number (ESN), mobile identification number (MIN), or other unique identification code assigned to each subscriber unit (112). When a call is received addressed to a subscriber unit having a particular telephone number, the corresponding SUIN, CSS status information, and the information of the last cellular site of that subscriber unit are determined, using the visitor's location directory. In response to this determination, a paging code is calculated in various ways depending on the CSS status information resulting from the subscribing unit that is being paged. If the subscriber unit being addressed is part of a CSS, the paging code used to generate the paging message is calculated in a first way in such a way that it is the same for each subscriber unit within a particular CSS. If the CSS status information indicates that the subscribing unit being paged is not part of a CSS, the paging code is calculated in a second form in such a way that it is different for each subscribing unit. A set of paging parameters is then calculated using the paging code which in the preferred embodiment includes a CDMA channel, a paging channel, and a paging slot. The page message is then transmitted in accordance with those paging parameters. In the preferred embodiment, the page message generation process using the paging parameters is the same as that of the cellular system of the prior art in order to maintain maximum compatibility with those systems of the prior art.