MXPA99005576A - Use of isdn to provide wireless office environment connection to the public land mobile network - Google Patents

Abstract

An integrated services digital network (ISDN) (62) connection is maintained between a wireless office environment (40) type private cellular telephone system and a public access cellular telephone system (12). In particular, an mB+D ISDN connection (where m=2, 23 or 30) is maintained between the ISDN network and each of a wireless office environment mobile switching center (WOE-MSC) (42), a public land mobile network mobile switching center (PLMN-MSC) (14) and a home location register (PLMN-HLR) (22). A protocol converter (72) is provided in each of these nodes to convert between the Transaction Capabilities Applications Part (TCAP) message Signaling Connection Control Part (SCCP) supported signaling system no. 7 (SS7) message formats and the ISDN format. During registration, call delivery and hand off, an ISDN call (108, 118, 202, 302) communication is established between the wireless office environment type private cellular telephone system and the public access cellular telephone system. The SS7 messages are then exchanged between the systems over the D channel. Any necessary speech connection is then carried over one of the m available B channels.

Description

USE OF ISDN TO OFFER A CONNECTION OF THE INAL MBRICO ENVIRONMENT WITH THE PUBLIC TERRESTRIAL MOBILE NETWORK BACKGROUND OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to wireless office environments as well as to public land mobile networks and, particularly, to the interconnection of a wireless office environment and a public land mobile network through an integrated services digital network (ISDN). DESCRIPTION OF THE RELATED TECHNIQUE Public access cellular telephone systems are currently available for use throughout the world. Partly as a result of the success of such systems for providing mobile telecommunications services to the public, considerable interest has emerged in the business sector to provide a wireless communication feature added to conventional private wireline telephony systems. Such a characteristic is typically implemented through the use of a private cellular telephone system. Due to the cost of mobile terminals, it is preferable that a private cellular telephone system established by a company employs the same types of mobile terminals as the terminals + used with publicly available and readily available cellular telephony systems. In addition, because many employees already have mobile terminals and have subscriptions with a public access cellular telephone system, it is preferable that the mobile stations used can operate within each of the systems and between each of the systems. At a minimum, this requires that the private cellular telephone system operates within the same cellular frequency band as the public access cellular telephone system, and uses the same type of switching equipment and base stations or switching equipment and compatible base stations. It is also likely that the radio frequency coverage regions of the private cellular telephone system and public access cellular telephone system can at least partially be joined.

In addition, the private cellular telephone system and the public access cellular telephone system must communicate with each other regarding the service of mobile stations, the allocation of channels (frequency) for communication, the routing of communications, and the transfer of communications from mobile stations. To transfer messages according to the provisional standard TIA / EIA IS-41 (as well as another signaling system number 7), the El / Ti connection modulated by permanent pulse code is typically used to connect between the private cellular telephone system and the public access cellular telephone system. The cost of increasing this connection is typically absorbed by the provider of the private cellular telephone system. In the case of private cell phone system providers that have many employees, the five to ten thousand dollars per year charge per year for the El / Tles connection reasonable and acceptable. In the case of private cell phone system providers with few employees, which are often referred to as the implementation of "a wireless office environment" (WOE), the cost of maintaining the El / Ti connection with the mobile phone system of Public access may not be justified.

Accordingly, there is a need for a more economical connection mechanism between a private cellular telephone system of the wireless office environment type and the public access cellular telephone system. Furthermore, in order to support interoperability, there is a need to use the most economical connection to effect the transfer of communications between the private cellular telephone system of the wireless office environment type and the public access cellular telephone system, the registration of the mobile stations that operate there, and the supply of calls to such mobile stations. COMPENDIUM OF THE INVENTION To meet the aforementioned needs, the present invention employs an Integrated Services Digital Network (ISDN) connection between a wireless cellular environment type private cellular telephone system and a public access cellular telephone system. This connection can be obtained through the service provider at a much lower cost than an El / Ti connection. An ISDN connection mB + D (where m = 2, 23 or 30) is maintained between a wireless office environment mobile switching center (WOE-MSC) and both a mobile public land mobile network switching center (PLMN-MSC) ) as your home location record (PLMN-HLR). Since the ISDN connection mB + D does not support the transmission of messages from the provisional standard TIA / EIS IS-41 (as well as another signaling system number 7 - SS7), a protocol converter is provided in the mobile switching center of wireless office environment, public land mobile network mobile switching center, and public land mobile network origin location record for the purpose of converting between the Transaction Capability Application Part (TCAP) message format of IS messages -41 (and other messages of type SS7) and the ISDN format. In particular, the protocol converter emulates the primitives offered by the Signaling Connection Control Part (SCCP) and functions to encapsulate TCAP messages within ISDN packets for transmission in the ISDN connection mB + D. Upon receipt, a corresponding protocol converter de-encapsulates the TCAPs between the received ISDN packets for processing. The protocol converters therefore allow the ISDN connection mB + D to behave as the Message Transfer Part (MTP) in relation to the transmission of IS-41 messages (and other SS7). When the need arises to transfer a communication between the wireless cellular environment type private cellular telephone system and the public access cellular telephone system, register a mobile station or carry out a call supply, a call is initiated ISDN from the mobile switching center of one system to the mobile switching center of the other system using the ISDN connection mB + D. The required IS-41 and other messages (SS7) is then exchanged on channel D to carry out the designated function. Any voice connection required in relation to this function is carried out on one of the m available B channels. BRIEF DESCRIPTION OF THE DRAWINGS A more thorough understanding of the method and apparatus of the present invention can be obtained with reference to the following Detailed Description when taken in combination with the Annex Drawings where: Figure 1 is a schematic diagram of a wireless communication system which includes a wireless cellular environment type private cellular telephone system and a public access cellular telephone system; Figure 2 illustrates the use of the message protocol signaling system number 7 (SS7) to transport IS-41 in an El / Ti connection; Figure 3 illustrates the use of the message sending protocols of the present invention to carry messages IS-41 (and other SS7) in an ISDN connection; Figure 4 is a diagram of node operation and signal flow illustrating an exchange transfer of a communication from a private cellular telephone system of wireless office environment type to the public access cellular telephone system; Figure 5 is a diagram of node operation and signal flow illustrating an exchange transfer of a communication from a public access cellular telephone system to a wireless cellular type of private office system type wireless telephone system; Figures 6A and 6B are diagrams of node operation and signal flow illustrating the termination of an incoming call; Figure 7 is a diagram of node operation and signal flow illustrating the registration of a mobile station. DETAILED DESCRIPTION OF THE DRAWINGS Referring now to Figure 1, there is shown a schematic diagram of a wireless communication system 10 that includes a public access cellular telephone system 12. (such as what is known as the public land mobile network - PLMN) the public access cellular telephone system 12 includes a plurality of interconnected switching nodes 14 frequently known as mobile switching centers (PLMN-MSCs). Although only two mobile switching centers 14 are illustrated, it will be understood that system 12 will probably include many more interconnected nodes. The first and second mobile switching centers 14 (1) and 14 (2) may comprise any of several known telecommunications switching devices, including devices frequently employed and known in the art to provide cellular telephony service either digitally or digitally. analog to a plurality of mobile stations (MS) 16. The mobile switching centers 14 are interconnected to each other for communication through voice trunks 18 (illustrated with interrupted lines) and signaling links 20 (illustrated with solid lines), which provide together a known ISUP type connection (or Rl or R2). The voice trunks 18 offer voice and data communications paths used to carry out subscriber communications between the mobile switching exchanges 14. The signaling links 20 carry command signals (for example, IS-41 messages or other signaling). system number 7 SS7) between the mobile switching centers 14. These signals can be used, for example, to establish and break voice and data communications links in the voice trunks 18 and to control the supply of call services to the stations 16. The mobile communication centers 14 are also connected to a database 22 consisting of a source location register (PLMN-HLR) by means of signaling links 24 providing a known IS-41 type connection (or well other SS7). The database 22 stores the information regarding the mobile stations 16 that comprise location information as well as service information. In a cellular system implementation, which is usually illustrated at 26, the mobile switching center 14 is additionally connected to at least one associated base station controller (BSC) 28 through a signaling link 30 and a truncal link 30. voice 32. Only a base station controller 28 is illustrated connected to the mobile switching center 14 (2) in order to simplify the illustration. The voice truncal 32 provides a voice and data communications path that is used to carry out subscriber communications between the second mobile switching center 14 (2) and its base station controller 28. The signaling link 30 carries command signals (such as SS7 messages) between the node 14 and its associated base station controller 28. The link signaling 30 and truncation 32 are collectively known in the art as "interface A". The base station controller 28 is then connected to a plurality of base stations (BS) 34 which operates to perform radio frequency communications with mobile stations located in close proximity 16 to an air interface 36. The base station controller 28 works in a well-known manner to control this operation of radio frequency communications. In another implementation of cellular system, which is generally illustrated at 38, the mobile switching center 14 (1) is additionally connected to a plurality of base stations (BS) 34 operating to perform radio frequency communications with mobile stations located near 16 on the radio interface. air 36. In this implementation, the functionality provided by the base station controller 28 (see generally at 26) provided by the mobile switching center 14. Even when direct communication links are illustrated (signaling and / or truncation) for the system 12 of Figure 1 the experts in the field understand that the links are not necessarily direct between the illustrated nodes, and can pass through many other communication nodes (not illustrated) of the mobile network and perhaps use other communication networks (such as the public switched telephone network - PSTN.) The illustration of the links in the manner illustrated in figure 1 is therefore only a simplification of the drawing. 10 further includes a wireless cellular environment type private wireless telephone system 40. A switching node 42, commonly known as a mobile switching center (WOE-MSC), is included in the system 40. The mobile switching center 42 can comprise any of several known telecommunication switching devices, including commonly used and known devices in the art because they already provide digital or analogue cellular telephone service to a plurality of mobile stations (MS) 16 '. In a first implementation, generally illustrated at 44, the mobile switching center 42 is connected to at least one associated base controller (BSC) 46 via a signaling link 48 and a voice trunk 50. Only one controller base station 46 is illustrated connected to a mobile switching center 42 in order to simplify the illustration. The voice truncation 50 provides a voice and data communications path that is used to carry subscriber communications between the mobile switching center 42 and its base station controller 46.

The signaling link 48 carries command signals (such as SS7) between the node 42 and its associated base station controller 46. The signaling link 48 and the truncation link 50 are commonly collectively known in the art as "interface A". » The base station controller 46 is then connected to a plurality of base stations (BS) 52 operating to perform radio frequency communications with mobile stations 16 'located near the air interface 36. The base station controller 46 it works in a well known way to control this radio frequency communication operation. In an alternative implementation that is generally illustrated at 54, the mobile switching center 42 is connected to a plurality of base stations (BS) 52 operating to perform radio frequency communications with mobile stations located near 16 'through the air interface 36. In this implementation, the functionality provided by the base station controller 46 (see, generally at 44) is provided by the mobile switching center 42. The system 40 also includes a private branch office (PBX) 56 connected to the mobile switching center 42 and that can operate to provide wireless telephony services to a plurality of user terminals (Uts) 58. The private branch exchange 56 functions in a well-known manner to allow a terminal of user 58 comes into contact with another user terminal through the dialing of an extension number. The private branch exchange 56 also functions to supply incoming calls from a public switched telephone network (PSTN) 60 to a particular user terminal 58 (perhaps through the use of direct inward dialing or through assistance of operator). The private branch exchange 56 further functions to allow a user terminal 58 to initiate a call to the public switched telephone network 60 (perhaps from the use of forward dialing or through the support of the operator). The configuration of the private branch exchange (PBX) 56 to carry out the aforementioned telecommunications services is well known to the experts in the matter. The public access cellular telephone system 12 and the wireless office environment type private cellular telephone system 40 are interconnected through an integrated services digital network (ISDN) 62 (instead of a conventional El / Tl connection as in the prior art). The connection of the wireless office environment type private cellular telephone system 40 to the integrated services digital network 62 is made from the mobile switching center (WOE-MSC) 42 using an ISDN 64 basic rate access connection. + D. The connection of the integrated services digital network 62 to the corresponding mobile switching center 14 (2) (PLMN-MSC) of the public access cellular telephone system 12 is performed by using an ISDN connection 66 either access-rate basic 2B + D or access primary rate nB + D (where n = 23 or 30). In a similar way, the connection of the integrated services digital network 62 with the database (PLMN-HLR) 22 of the system 12 of public access cellular telephony is carried out through the use of an ISDN connection 66 either access base rate 2B + D or access primary rate nB + D (where n = 23 or 30). The choice of basic or primary rate access for the ISDN connection 66 between the integrated services digital network 62 and the public access cellular telephone system 12 depends on the number of wireless office environment type cell phone system 40 that they share the coverage of radio frequency communications (in whole or in part) with the public access cellular telephone system. The integrated services digital network 62 is additionally connected to the public switched telephone network 60 or more particularly comprises a part of said network 60. The operation of the wireless cellular office type private cellular telephone system 40 offers services of mobile cellular communications only to mobile stations 16 '. In order to maintain the "private" aspect of the operation of the system 40, the mobile stations 16 that are not authorized for communication do not receive access to the cellular type system of the wireless office environment private type. However, some are that all of the mobile stations 16 'can have subscriptions of cellular services that allow access to the public access cellular telephone system 12. Accordingly, the mobile stations 16' can perform operations on both systems and are authorized to perform them. Since the mobile stations 16 'are by definition "Mobile", there will arise cases in which its owner subscribers can move between the service area of the public access cellular telephone system 12 and the service area of the cellular wireless system type of wireless office environment type 40. When In an inactive mode, the mobile stations 16 'are simply dedicated to the selection of services as is well known to those skilled in the art to choose the most appropriate base station 34 or 52 with which to communicate. When making a call communication, however, the movement of the mobile station 16 may result in the need to carry out a transfer between exchanges of the communication in progress. For example, as a result of the movement of the service area of the wireless office environment type private cellular telephone system 40 to the service area of the public access cellular telephone system 12 (as illustrated by arrow 68) , an inter-central transfer of the call occurs from the mobile switching center 42 to the mobile switching center 14. Conversely, as a result of the movement from the service area of the public access cellular telephone system 12 to the area of the wireless cellular environment type of private cellular telephone service system 40 (as illustrated by arrow 70), an inter-central transfer of the call occurs from the switching center 14 to the mobile switching center 42 In a conventional cellular communications system, this inter-core transfer is achieved through the exchange of messages of type IS-41 (or other SS7 type) 90 between the anchor and the mobile service switching centers employing well-known signaling system message transfer protocols number 7 (SS7) as illustrated in FIG. 2. In this configuration, the Signage Connection Control Part (SCCP) 92 is used with the Message Transfer Part (MTP) layer 94 to route formatted IS-41 (or other SS7 format) messages 96 of Capability Application Part 96 Transaction (TCAP) from end to end.

The integrated services digital network 72 however can not provide a means of transport for messages of type IS-41 in accordance with the signaling protocols of signaling system number 7 (SS7). The SCCPE layer 92 and the MTP layer 94 can therefore not be used for end-to-end routing of messages 90 formatted according to IS-41 (or other SS7) of TCAP 96 layer in an ISDN connection mB + D (where m = 2, 23 or 30). In accordance with the present invention, as illustrated in FIG. 3, a signaling connection Control Part emulation layer 92 '(SCCPE) is employed with an ISDN Transport layer 98 (ISDNT) for routing formatted messages 90. according to IS-41 of End-to-End Transaction Capability Application Part (TCAP) 96 layer through the digital services 62 network integrated in the ISDN connection mB + D. The SCCPE layer 92 'emulates the primitives offered by the SCCP layer 92 operates with the ISDNT layer 98, to encapsulate TCAP layer 96 messages with ISDN packets for transmission on the D channel. Even though the present invention has been presented herein in In the context of supporting the transmission of sending IS-41 messages in an ISDN-type connection (see Figure 3), it will obviously be understood that the protocol converter 72 (comprising the SCCP 92 'emulation layer and the ISDNT 98 layer) supports communication in the ISDN connection of any message sending based on system signaling number 7 supported by SCCP (including, but not necessarily limited to, sending Smart Application Part message and sending Mobile Application Part message) (MAP)). It will be further understood that the present invention allows the support of all other procedures of type IS-41 (for example, authentication). Referring again to Figure 1, to implement the above, the SCCPE layer 92 'and the ISDNT layer 98 together comprise a protocol conversion functionality 72 installed in each of the corresponding mobile switching centers 24 (2) (PLMN -MSC), the home location register (PLMN-HLR) 22, and the wireless office environment mobile switching center (WOE-MSC) 42 to allow message transport of type IS-41 (or other types) of SS7-based messages) on the D-channel of ISDN connections 74 and 76 mB + D (where m = 2, 23 or 30). Voice communications, if necessary, are transported on one of the m available B channels of the ISDN type connections mB + D 64 and 66. In addition, to support the development of ISDN-type connections between the cellular access system public 12 and the private office wireless type cellular telephone system 40, each of the corresponding mobile switching centers 14 (2) (PLMN-MSC), the home location register (PLMN-HLR) 22, and the wireless office environment mobile switching center (WOE-MSC) 42 receives an ISDN type address comprising a number of directory telephones. These ISDN-type addresses are used by the protocol conversion functionality 72 (instead of source and destination point codes as used in sending messages of type SS7 in FIG. 2) to direct information packets for its transmission through the integrated services digital network 62. If necessary, a conversion table is kept by the cooperative mobile switching center 14 (2) (PLMN-MSC), the home location register (PLMN- HLR) 22, or the wireless office environment mobile switching center (WOE-MSC) 42 for transferring a destination point code for a particular node either in the public access cellular telephone system 12 or in the wireless office environment type private cellular telephone system 40 to its corresponding assigned ISDN address. Reference is now made to FIGS. 1 and 4. FIG. 4 is a flow diagram illustrating the transfer of a mobile station 16 'from a wireless cellular environment type private wireless telephone system 40 to a wireless system. public access cellular telephony 12 (see, arrow 68). An ongoing call communication 100 is carried out through a selected traffic channel through the base station 52. By monitoring the signal strength measurements that are performed either by the base station 52 (in the uplink) and / or the mobile station 16 '(in the downlink), the base station determines whether a transfer is required (action 102) due to the decrease in signal strength characteristics at the air interface 36 carrying the communication 100. If the determination is affirmative, the base station 52 transmits a transfer request 104 to its mobile switching center (WOE-MSC) 42. In response to the request, the mobile switching center 42 determines when the transfer should occur (action 106). This determination is made by the identification of neighboring cells in relation to the current service cell, and maybe by evaluating downward signal strength measurements that are made in relation to these cells by the mobile station 16 '. In the present invention of transfer, neighboring cells identified include cells within the wireless cellular environment type private office system 40 (served other base stations 52) and to handle a cell within the public access cellular telephone system 12 (served by a base station 34).

Since a cell within a public access cellular telephone system 12 is identified as a candidate for transfer, the mobile switching center 42 establishes a call connection 108 with the cooperative mobile switching center (PLMN-MSC) 14 (2) of the public access cellular telephone system. Using the channel D of the connections mB + D 64 and 66 as well as the protocol converters 72, the two mobile switching centers 14 (2) and 42 exchange signaling of type IS-41 (or other signaling of type SS7) required in relation to the performance of a verification signal strength measurement by the base station 34. This signaling includes a request 110, sent by the mobile switching center 42, for a verification signal strength measurement 112 to be processed by the base station 34, as well as a report 114, sent by the mobile switching center 14 (2), in the measurement made by the base station. The call connection 108 can be suspended at this point, if desired. At the same time the mobile switching center 42 requests 110 the elaboration of a verification signal strength measurement 112 by each of the base stations 52 for the candidate cells identified within the private cellular telephone system 40 of the wireless office environment. The reports 114 on the verification signal strength measurements made in the base station 52 are subsequently received subsequently. By processing all 114 reported signal strength measurements, the mobile switching center 42 identifies (action 116) a preferred target cell for the transfer. It is considered for the purposes of this example, that the mobile switching center 42 identifies a cell associated with a base station 34 within the public access cellular telephone system 12 as a preferred target. If the call connection 108 is not yet established, the mobile switching center 42 establishes a new call connection 118 with the cooperative mobile switching center 14 (2) of the public access cellular telephone system. Otherwise, the existing call connection 108 is employed. Using the D channel of the mB + D connections 64 and 66, the two mobile switching centers 14 (2) and 42 then exchange the IS-41 signaling. (or another signaling of type SS7) required to effect the transfer. This signaling includes a request 120, made by the mobile switching center 42, for the assignment (and reservation), by the mobile switching center 14 (2), of a traffic channel for transfer to the target cell (served by the base station 34). A traffic channel (action 122) is then taken, both the base station 34 and the mobile switching center 42 are informed 124 of the assignment by the mobile switching center 14 (2) as to the traffic channel in a white cell. The mobile switching center 42 then signals the mobile station 16 'through the base station 52 for the current service cell with a transfer command directing instructions to the mobile station to switch to the assigned traffic channel in the white cell. The mobile station 16 'is then tuned to the assigned traffic channel and has access 128 to said channel. When the base station 34 detects mobile station access (action 130) the mobile switching center 14 (2) is informed 132. A signal 134 indicating the same is then sent by the mobile switching center 14 (2) to the mobile switching center 42 on the D-channel of the connections mB + D 64 and 66. The call communication 100 is then switched 136 to the mobile switching center 14 (2) on one of the m available B channels of the connections mB + D 64 and 66 providing a call connection 208 or 118 for additional handling with the object to finish the transfer procedure. Reference is made to Figs. 1 and 5. Fig. 5 is a flow chart illustrating the transfer of a mobile station 16 'from the public access cellular telephone system 12 to the private cellular telephone system of the wireless office environment 40 (see arrow 70). An ongoing call communication 100 is being carried out on a selected traffic channel through the base station 34. Through the monitoring of signal strength measurements that is carried out either by the base station 34 ( in the uplink) and / or through the mobile station 16 '(in the downlink), the base station determines if a transfer is required (action 102) due to the decrease in signal strength characteristics at the air interface 36 that carries out the communication 100. If the determination is affirmative, the base 34 transmits a transfer request 104 to its mobile switching center (PLMN-MSC) 14 (2). In response to the request, the mobile switching center 14 (2) determines when the transfer could and / or should occur preferably (action 106). This determination is carried out by identifying cells neighboring the current service cell, and perhaps by evaluating downlink signal strength measurements in relation to the cells through the mobile station 16 '. In the present transfer situation, the neighbor cells identified include cells within the public access cellular telephone system 12 (served by other base stations 34) and at least one cell within the private cellular telephone system 40 of the environment type of wireless office (served by a base station 52). Since a cell within the private cellular telephony system 40 of the wireless office environment type is identified as a candidate for transfer, the mobile switching center 14 (2) establishes a call connection 108 with the cooperative mobile switching center (WOE). -MSC) 42 of the private cellular telephone system of the wireless office environment type. Using the channel D of the connections mB + D 64 and 66 as well as the protocol converters 72, the two mobile switching centers 14 (2) and 42 exchange the required signaling IS-41 (or other SS7) in relation to the processing of a verification signal strength measurement by the base station 52. This signaling includes a request 110, sent by the mobile switching center 14 (2), to perform the measurement of a verification signal strength 112 by the base station 52, as well as a report 114, sent by the mobile switching center 42, on the measurement made by the base station. The call connection 108 may be abandoned at this point, if desired. At the same time, the mobile switching center 14 (2) requests 110 the marking of a verification signal strength measurement 112 for each of the base stations 34 for candidate cells identified within the access cellular telephone system 12. The reports 114 on the verification signal strength measurements made by the base station 34 are then received.With the processing of all the reported signal strength measurements 114, the mobile switching center 14 (2) identifies ( 116) a preferred target cell for transfer It is considered for purposes of this example, that the mobile switching center 14 (2) identifies a cell associated with the base station 52 within the private cellular telephone system 40 of the wireless office environment as preferred target.If call collection 108 is not yet established, mobile switching center 14 (2) is a new call connection 118 is established with the cooperative mobile switching center 42 of the wireless cellular environment type private cellular telephone system. Otherwise, the existing call connection 108 is used. Using the connections channel mB + D 64 and 66, the two mobile switching centers in 14 (2) and 42 then exchange the signaling of type IS-41 (or another signaling of type SS7) required to carry out the transfer. This signaling includes a request 120, made by the switching center 14 (2), for the assignment (and reservation), by the mobile switching center 42, of a traffic channel for the transfer to the target cell (served by the base station 52). Then a traffic channel is taken (action 122), and both the base station 52 and the mobile switching center 14 (2) are informed 124 of the assignment by the mobile switching center 42 regarding the traffic channel in the target cell. The mobile switching center 14 (2) then signals the mobile station 16 'through the base station 34 for the cell currently in service with a transfer command that instructs the mobile station to switch to the slave channel. assigned traffic in the white cell. The mobile station 16 'then tunes and has access 128 to the assigned traffic channel. When the base station 52 detects the mobile station access (action 30), the mobile switching center 42 is informed 132. A signal 134 indicative thereof is then sent to the mobile switching center 42 to the mobile switching center 14 ( 2) on the channel D of the connections mB + D 64 and 66. The call communication 100 is then switched to the mobile switching center 42 on one of the available B channels of the connections mB + D 64 and 66 providing connection Call 108 or 118 for additional handling to complete the transfer procedure. Referring now in combination to FIGS. 1 and 6A and 6B, FIGS. 6A and 6B are signal flow diagrams and node operations for terminating an incoming call. A call 200 dialed to the directory number (number B) of a mobile station 16 'originates from a central private branch 56 and is received at the mobile switching center (WOE-MSC) 42. Using the digital network of integrated services 62, the mobile switching center 42 establishes a call connection 202 with the home location register (PLMN-HLR) 22. Using the D channel of the mB + D connections 64 and 66, the mobile switching center 42 interrogates the source location registration database 20 with the location request message (send routing) 204. The location request message 204 (send routing) is processed by the source location register 22 to determine the location (ie, the mobile service switching center) of the mobile station called 16. The determined mobile service switching center may comprise the mobile switching center (WOE-MSC) 42 (see 6A) or one of the mobile switching centers (PLMN-MSC) 14 (see figure 6B). Referring now to Figure 6A, the source location register 22 then recognizes (action 218) from the location processing that the mobile switching center 42 is functioning as a gate switch for the call as well as a service switching node for the call. the mobile station called 16 'in relation to the incoming call 200. The message 212 is then sent to the originating mobile switching center 42 on the D-channel of the connections mB + D 64 and 66 from the home location register 22 with a resulting code that indicates the above. Accordingly, the assignment of any temporary location directory number (TLDR) in this case is not required. The incoming call is then supplied (connected) 214 using the routing number to the mobile service switching center 42 for termination attempt to the mobile station called 16 '. The termination of the call includes an additional routing 216 of the incoming call to the current base station 52 and then to the mobile station 16 'on the air interface 36. Turning now to Figure 6B, the home location register 22 indicates the mobile service switching center 14 for the mobile station 16 'on the signaling link 24 with the routing request message (provide offset) 206 for preparing the call. The mobile service switching center 14 then selects in the action 208 an appropriate number of routing (e.g., a temporary location directory number (TLDN) or offset number). The selected routing number is then returned 210 and 212 to the originating mobile switching center 42 on the signaling link 24 and D-channel of connections mB + D 64 and 66 through the home location register 22. Using the digital network of integrated services 62, the mobile switching center 42 establishes a call connection 218 with the cooperative mobile switching center 14 (2) which is extended, if necessary, to the mobile service switching center 14 through the trunk 18 and signaling link 20. The incoming call is then supplied (connected) 220 on one of the m available D channels of the mB + D connections 64 and 66 and the voice trunk 18 which employs the routing number to the switching center service mobile 14 for termination attempt towards the mobile station called 16 '. The termination of the call includes the additional routing 222 of the incoming call to the current service base station 34, and then to the mobile station 16 'on the air interface 36. The storage update (action 310) of data Relevant is further carried out in the home location register 22. Referring now to Figures 1 and 7, Figure 7 is a diagram of node operation and signal flow illustrating the registration of a mobile station. A mobile station 16 'now registers with the system 10 by transmitting a registration message 300 to the mobile service switching center (WOE-MSC) 42 via the service base station 52 (and perhaps the service base station controller 46). In response to this, the mobile switching center 42 establishes a call connection 302 with the home location register (PLMN-HLR) 22. Using the D channel of the mB + D connections 64 and 66, the mobile switching center 42 sends a registration warning message 304 to the source location register 22 requesting the subscriber profile associated with the mobile registration station 16 '. The home location register 22 retrieves the subscriber profile and sends the information back to the requesting mobile switching center 42 in a message 306 transmitted back on the D channel of the mB + D connections 64 and 66. The subscriber profile is then stored (action 308) in a visitor location register (not illustrated) associated with the mobile service switching center 42. Although preferred embodiments of the method and apparatus of the present invention were illustrated in the accompanying drawings and described in the Detailed description above, it will be understood that the invention is not limited to the modalities presented, but can be carried out with numerous rearrangements, modifications and substitutions without departing from the spirit of the invention presented and defined in the appended claims.

Claims (2)

1. CLAIMS A wireless communication system, comprising: a private cellular telephone system providing service only to first mobile stations, the private cellular telephone system includes a first switching node connected to a plurality of first base stations in radio communication frequency for the first mobile stations; a public cellular telephone system that provides service to second mobile stations, the second mobile stations include at least one first mobile station, the public cellular telephone system includes a second switching node connected to a plurality of second base stations in communication by radio frequency with the second mobile stations and with at least one first mobile station, the second switching node is further connected to a home location register; an integrated services digital network interconnecting the first switching node, the second switching node and the originating location register to carry out a communication message of system number 7 of reformatted signaling, which includes: a first connection mB + D with the first mobile switching center; a second connection mB + D with the second mobile switching center; and a third mB + D connection to the home location register; a first protocol converter for the first switching node connected to the first mB + D connection to provide Signaling Connection Control Part (SCCP) emulation functionality to format number 7 system signaling messages to communicate with the second switching node and home location register and from said second switching node and home location register in the integrated services digital network; a second protocol converter for the second switching node connected to the second connection mB + D to provide an SCCP emulation functionality for formatting system signaling messages number 7 for communication to the first switching node and home location registration and starting from said first switching node and originating location register in the integrated services digital network; and a third protocol converter for the home location register connected to the third mB + D connection to provide an SCCP emulation functionality for formatting system signaling messages number 7 for communication to the first and second switching nodes and from said first and second switching nodes in the integrated services digital network. The system according to claim 1, wherein m = 2, 23 or 30. The system according to claim 1, wherein the first, second and third connections mB + D include a D channel and where the D channel is used for carry out number 7 system signaling messages formatted by protocol converter between the first mobile switching center and the second mobile switching center and the home location register. The system according to claim 3, wherein the routed system 7 signaling messages comprise transfer signaling messages. The system according to claim 3. Where the addressed system 7 signaling messages comprise call delivery signaling messages. The system according to claim 3, wherein the routed number 7 system signaling messages comprise first mobile station registration signaling messages. The system according to claim 1, wherein the first connection and second connection in mB + D include m available B channels, and where each B channel can be used to carry out voice communications between the first mobile switching center and the second mobile switching center. A method for communicating signaling messages of systems number 7 in an integrated services digital network from a first communication coding node to a second communications switching node, comprising the steps of: establishing a call connection of integrated services digital network between the first communications switching node and the second communications switching node; converting in the first communication switching node a system signaling message number 7 originated into a format suitable for transmission on a D-channel of the integrated services digital network call connection; sending the message converted in channel D to the second communication switching node; and converting into the second communication switching node in converted message format received from the return channel to the source signaling system number 7 message. 9. The method according to claim 8, wherein the first communication switching node comprises a first cellular system switching node and the second communication switching node comprises a second cellular system switching node and the system signaling message number 7 comprises a cellular call supply signaling message. The method according to claim 8, wherein the first communication switching node comprises a first cellular system switching node, and the second communication switching node comprises a second cellular system switching node, and the message System signaling number 7 comprises a cell transfer signaling message. The method according to claim 8, wherein the first communication switching node comprises a cellular system switching node and the second communication switching node comprises a source location register, and the system signaling message number 7 comprises a cellular call supply signaling message. The method according to claim 8, wherein the first communication switching node comprises a cellular system switching node and the second communication switching node comprises a source location register, and the system signaling message number 7 comprises a mobile station registration message. A method for carrying out the transfer of a mobile station call from a first cellular communication system to a second cellular communication system, where the first cellular communication system and the second cellular communication system are interconnected by a integrated services digital network, comprising the steps of: establishing an integrated services digital network call connection between communication switches of the first cellular communication system and the second cellular communication system; exchanging transfer signaling messages based on system number 7 signaling between the communication switches of the first cellular communication system and the second cellular communication system through transferred signaling message trassions converted to a D channel of the call connection of digital network of integrated services established; and routing the mobile station call between the communication switches of the first cellular communication system and the second cellular communication system on a P channel of the integrated services digital network call connection established to effect the transfer. The method according to claim 13, further including the steps of: converting into one of the communication switches of the first communication system or second cellular communication system a message related to the transfer of signaling of systems number 7 to a format for trassion on channel D of the established connection of integrated services digital network calls; send the converted message on channel D; and converting the message format converted back to the related message of system signaling transfer number 7 into the other of the communication switches of the first cellular communication system or second cellular communication system. The method according to claim 13 , where the transfer signaling messages based on signaling of number 7 systems comprises requests for verification signal strength measurement. The method according to claim 13, wherein the transfer signaling messages based on system signaling number 7 comprise channel assignment requests. . The method according to claim 13, wherein the Transfer signaling messages based on system number 7 signaling include access reports to mobile stations. A method for supplying an incoming call received in a communications switch of a first cellular communication system to a mobile station served by a communications switch of a second cellular communication system where the communication switches of the first cellular communication system and second Cellular communication system are interconnected through a digital network of integrated services, comprising the steps of: establishing an integrated services digital network call connection between the communication switches of the first cellular communication system and the second cellular communication system; exchanging call supply signaling messages based on system number 7 signaling between the communication switches of the first cellular communication system and the second cellular communication system through transmission of call delivery signaling messages converted into a D-channel of the established integrated services digital network call connection; and routing the incoming call between the communication switches of the first cellular communication system and the second cellular communication system on a D-channel integrated services digital network call established for supply to the mobile station by the second cellular communication system . The method according to claim 18, further comprising the steps of: converting into one of the communication switches for the first cellular communication system or second cellular communication system a message related to the provision of signaling calls of number systems 7 to a format for transmission on the D-channel of the established integrated services digital network call connection; sending the message converted to channel D; and converting into the other of the communication switches "for the first cellular communication system or second cellular communication system the converted message format returned to the message related to the provision of system signaling call number 7. The method of conformity with Claim 18, wherein the call supply signaling messages based on system signaling number 7 comprise mobile station location requests. . The method according to claim 18, wherein the call delivery signaling messages based on system signaling number 7 comprise call routing requests. A method for registering a mobile station served by a communication switch of a first cellular communication system with a home location register of a second cellular communication system where the communication switch and the home location register of the first system of cellular communication and second cellular communication system, respectively are interconnected through a digital network of integrated services, which comprises the steps of: establishing a connection of calls integrated services digital network between the communications switch and the location register of origin of the first cellular communication system and second cellular communication system; and exchanging record signaling messages based on system number 7 signaling between the communications switch and the home location register of the first cellular communication system and the second cellular communication system through transmissions of registration signaling messages converted into a D channel of the integrated services digital network call connection established to register the mobile station in the home location register. The method according to claim 22, further including the steps of: converting into one of the communications switch or source location register of the first cellular communication system or of the second cellular communication system, a message related to registration signaling system number 7 to a format for transmission on the D-channel of the established integrated services digital network call connection; send the converted message on channel D; and converting the message format converted back to the message related to system signaling register number 7 into the other of the communication switch or either the home location register of the first cellular communication system or the second cellular communication system. method according to claim 22, wherein the registration signaling messages based on system signaling number 7 comprise registration warning messages. The method according to claim 22, wherein the registration signaling messages based on signaling system number 7 comprise subscriber profile information.