Switching centre for mobile radio application.

Switchboard for car radio use - Växelstation för radiomobelefonbruk

The invention relates to the connection of mobile subscribers in a cellular radiotelephone system to the public telephone network.

In an article by G. Söderholm, J. Widmark and E. Ornulf, Ericsson Cellular Mobile Telephone Sys10 tems, published in Ericsson Review, no. B 1987, pages 42-49 shows a switching system for mobile subscribers in which radio connections are provided by assigning a subscriber a specified frequency for the duration of the call.

In this system, functions related to both the control of mobile subscribers and telephone connections (voice and data) are integrated in the same unit.

In an article by P. Duplessis and F. Maillard, The Pan-European Digital Cellular System for Radiotelephony with Mobiles, published in Commutation et Transmission, Nr. 2,

1988, pages 5-14 describe the connection of mobile subscribers: ^; system in which radio links are produced using: time division multiple access (DTMA). In this system, the control functions related to subscriber mobility and the functions related to communication are implemented in the same unit.

* · · • · • · · • · * * * In both systems, the same gear handles both switching operations and processing operations related to subscriber mobility. There are several disadvantages to this integration:

it requires the use of special switches, the switch requires a considerable amount of processing capacity, which is very sensitive to subscriber mobility and cellular network topology, the processing capacity required for signaling is highly related to subscriber mobility without any switching measures, difficulties in controlling each application, maintenance and upgrade.

The object of the invention is to avoid the disadvantages of known systems.

The invention comprises a switching center for a mobile telephone application for connecting mobile subscribers to a public telephone network, which switching center is connected via first multiplex connections to controllers, which in turn are connected to base stations in radio communication with mobile subscribers, and a telephone network via second multiplex connections for transmitting data speech signals, da25 tan and signaling, including signaling related to switching functions and signaling related to fixed registers of mobile subscribers and temporary registers of mobile subscribers in a given geographical area and other switching centers in said geographical area, in which case the signaling of the first and second multiplex connections is transferred to CCITT no. 7 using a signaling system; comprising a service paging switch and a mobile telephone control point connected by a multiplex connection, which service branch35 image only provides switching functions and which mobile telephone control point produces only signaling related to the mobile telephone application, wherein the switching switch forms:

-semi-permanent connections between the interconnected multiplex connection and other multiplex connections for the exchange of signaling related to registers and other switching centers;

- a permanent connection between the trunk multiplex connection and the signaling point of the service paging switch, which signaling point is also connected via permanent connections to other multiplex connections in order to exchange the signaling related to the switching functions; and

- semi-permanent connections between the trunk multiplex connection and the first multiplex connection to exchange signaling.

The switching center according to the invention has several advantages:

it allows the use of switchboards similar to those used in the public telephone network, by separating the switchboard application from the mobile application, each application can be updated separately, the switching efficiency is the same as in a conventional switchboard, the processing efficiency required for switching signaling is limited to switching functions the essential advantage is that that it allows direct access to the public telephone exchange by connecting the switch directly to the base station controllers and connecting it to a mobile control point, it also allows the use of a mobile control point common to several exchanges, even if the exchanges were 98482 different types, e.g. Alcatel E10 and S12, and only a single development cost for the mobile application, regardless of the stage used.

The invention will now be described, on the basis of an embodiment, with reference to the accompanying figures, in which:

Fig. 1 is a schematic diagram showing part of the architecture of a cellular mobile telephone system, FIG. 2 shows the logic connections of the switching center according to FIG. 1, FIG. 3 is a schematic diagram of a switching center according to the invention, FIG. Fig. 4 shows an alternative embodiment of the switching center according to Fig. 3, and FIG. 5 shows the use of a telephone exchange to perform switching center connections.

The cellular radiotelephone network is usually connected to the public switched telephone network RTPC. The radiotelephone network comprises the radio subsystem RSS and the network subsystem NSS, which is connected to or under the control of the radio subsystem RSS and which is also connected to the public voice network RTPC.

Figure 1 is a schematic diagram of a cellular radiotelephone network connected to the public switched telephone network RTPC.

The RSS subsystem comprises mobile subscribers 1, base stations 4 in radio communication with mobile subscribers, which base stations comprise radio receiver and ra98482 diode transmitter devices and base station controllers 5, each connected to base stations 4, which may be separate or integrated in controller 5. The connection between controller 5 and base stations 4 is Pulse code modulated (PCM) multiplex connection standardized by the European Conference of Postal and Telecommunications Administrations (CEPT). The controllers 5 provide a numerical summary of the network subsystem NSS to which they are connected by PCM multiplex connections and CEPT standardized interfaces, referred to as the “A interface”, which multiplex connections transmit voice signals, data and signaling CCITT no. 7 using a signaling system, which is a signaling channel signaling system defined by the CCITT for numerical networks and transmissions.

The network subsystem NSS comprises one or more switching centers 6, each of which forms an interface between the radio subsystem RSS and the telephone network RTPC, a permanent register 8 with mobile subscribers of the cellular radio network 20 and a temporary register 9 with those mobile subscribers located in the area shown in Figure 1. the switching centers 6 and the base stations 4 of the part of the radiotelephone network shown serve, which part may correspond to, for example, a geographical area.

The network subsystem NSS shown in Figure 1 also includes an operation and maintenance center 7, which forms part of the radiotelephone network. This operation and maintenance center is connected to each switching center 6 in the part of the radiotelephone network shown in Fig. 1. However, if a part of the radiotelephone network contains only one switching center, this switching center may be connected to an operation and maintenance center belonging to a different part of the radiotelephone network.

The switching center 6 is connected via the first multiplex connections 65 to the controllers 5, which multiplex connections transmit voice signals, data and signaling 98482 toa. The exchange is connected via the second multiplex connections 610 to the public switched telephone network RTPC, whereby the second multiplex connections transmit voice signals, data and signaling.

In the public switched telephone network RTCP there are transmission points CCITT no. 7 for signaling used by the radiotelephone application on the connections 616, 618 and 619 shown in Figure 2. Both the permanent mobile subscriber register 8 and the ti10 polar register 9, which contains those mobile subscribers in the geographical area of ​​the switching center 6 of the part of the radiotelephone network shown in Fig. 1, are connected to the switching centers via the public telephone network, whereby information is exchanged via signaling channels. The operation and maintenance center 7 of the switching centers 6 is connected to the switching centers via connections 76 and to the temporary and permanent registers via connections 78 and 79.

Figure 2 shows the logical connections of the connections connecting the switching center 6 of Figure 1 to the controllers 5 and the telephone network. The first multiplex connection 65 comprises a logical voice and data connection 65a and a logical signaling connection 65b. The second multiplex connections 610 comprise logical connections 610a for transmitting voice and data, logical signaling connections 610b for signaling associated with logical connections 610a, logical connections 616 for inter-exchange signaling to switch switching center 6 to other switching centers 6 of Figure 1, registration of the register, allowing access to said registers. Both the logical connection 65b used for signaling and the logical connections 610b, 616, 618 and 619 are for multiplex connections.

65 and 610 signaling channels. Logical connections 65a and 610a are channels of multiplex connections 65 and 610 other than signaling channels and, as already mentioned, the logical connections used for signaling 98482 use all CCITT no. 7 signaling system.

Naturally, the signaling transmitted by the signaling connections 610b could be a signaling used in the public telephone network, e.g. multi-frequency signaling.

Figure 3 shows a schematic diagram of a switching center 6 according to the invention, including a service paging switch 11 and a mobile telephone control point 12.

The service paging switch 11 is a switch of the same type as that used in current telephone networks, e.g. a Alcatel E10 or S12 switch. It is connected to the controllers 5 by first multiplex connections 65 and to the public telephone network by second multiplex connections 610. Figure 3 shows multiplex connections 65 and 610 as well as Figure 2 comprising several logical connections 65a & 65b and 610a, 610b, 616, 618 & 619. In addition, the service paging center 11 is connected by a connection 600 to the RTPC operation and maintenance center of the public telephone network.

The service paging switch 11 switches speech signals and data in both directions between the logical connections 65a and 610a, i.e. between the channels of the multiplex connections 65 and 610, and transfers signaling between the mobile control point 12 and the logical signaling connections 65b via semi-permanent connections.

The service paging switch 11 has a signaling point PS where it processes all the signaling transmitted via the logical signaling connections 610b in both call directions. It transmits signaling between the mobile control point 12 and the logical signaling connections 616, 618 and 619 on semi-permanent connections, which signaling is sent or received at the mobile checkpoint.

The mobile control point 12 thus processes all the signaling related to the radiotelephone application, whereby the service paging switch 11 processes only the signaling related to the voice and data5 channels of the logical connection 610a. The signaling point PS of the service paging switch 11 is permanently connected to the mobile telephone control point 12.

In Figure 3, the mobile control point 12 and the service paging step 10 are connected by a multiplex connection 601 comprising logical connections 125, 121, 126, 128 and 129 connected to a logical connection 65b, a signaling point PS and logical connections 616, 618 and 619, respectively.

The mobile access point 12 is also connected to the mobile access and service center 15 via connection 150. The mobile access and service center 15 is connected to a geographical part of the radiotelephone network and is therefore connected to the mobile access points 12 in the switching centers in this area. .

The service search switch 11 performs the following functions:

it provides a signaling point to the public switched telephone network to which it is connected by logical signaling connection 610b, it establishes level 1 routing of semi-permanent connections between mobile control point 12 and logical connections 65b, 616, 618, and 619, i.e. between first multiplex connections 65 and second multiplex connections it establishes an intelligent network-type connection to the mobile control point 12 to exchange information via the logical connection 121 of the multiplex connection 601; it responds to instructions sent by the mobile control point over the logical connection 121 to signaling entering or leaving logical connections 65b, 616, 618 and 619, but only establishes semi-fixed connections between these logical connections and the mobile telephone control point 12) and processes the operating instructions related to the operation of the public telephone network transmitted by the operation and maintenance center of said network to which it is connected via connection 600.

The mobile phone control point 12 performs the following operations:

it connects and processes everything in the mobile subsystem. RSS and network subsystem NSS mobile application,, 25 lux signaling

I » ¹ «* 1» Il I «·» • · · '· * * it performs all the functions related to the mobility of subscribers, ««' • · »e · · • c it acts as a national no. 7 as a signaling point for the network subsystem NSS mobile application, • · • · · * · *. it works as a local no. 7 as a signaling point for the mobile subsystem mobile application RSS, it controls the service paging switch 11 in subscriber mobility activities, it updates the temporary register 9 associated with mobile subscribers in the geographical area served by one or more switching centers , it monitors the mobile app, and it uses the mobile telephone application in connection with the operation and maintenance center of the mobile telephone application 15 to which it is connected, which operation is independent of the corresponding operation of the public telephone network.

The switching center structure according to the invention shown in Figure 3 enables the national subsystem NSS to have two different structures.

In the first embodiment, each switching center comprises a service paging switch 11 and a mobile telephone control point 12.

In the second embodiment shown in Fig. 4, each switching center comprises a service paging switch 11 and the mobile control points of the plurality of switching centers are connected at a common control point 120 connected by connections 601 to each service paging switch 11 and a connection 30 to a mobile telephone access and service center 15.

This second embodiment is made possible by the structure of the switching center according to the invention, in which the switching operation and the signaling of the mobile telephone application are separated and which are performed by two separate units.

The structure of the switching center according to the invention makes it possible

II f the use of a paging exchange of the type used in public telephone networks.

In Fig. 1, which shows a part of the mobile telephone network, the switching centers do not form part of the public telephone network RTPC but are connected to the exchanges of said public telephone network, as it has previously been customary to use special mobile switching centers.

However, as shown in Fig. 5, the structure of the switching center according to the invention enables the use of telephone network switches C in a mobile telephone application. The exchanges C are then directly connected to the controllers 5 of the base stations 4. They are also connected to a common mobile telephone point 120, which control point is common to several exchanges in the same geographical area. Naturally, the control point could be connected to only one gear C.

The invention thus makes it possible to eliminate switching centers in the mobile telephone network, at least in most cases. There may always be cases for specific reasons due to geographical coverage, where switching centers are used that are connected to the telephone network in the way that is now used in mobile telephone networks.