FI103370B - Procedure for maximizing the V5 interface's accessible capacity in wireless subscriber network environment - Google Patents

Description

103370 METHOD FOR MAXIMIZING THE AVAILABLE CAPACITY OF THE V5 INTERFACE IN A WIRELESS LAN

The present invention relates to a method for maximizing the available capacity of a 5 V5 interface in a wireless access network environment, wherein the terminal is radio-connected to the base station and thereby further to the access network element and the telephone exchange.

10 In WLAN, Wireless

Local Loop) is connected to the access node by radio connection. Between the terminal and the subscriber network element there is a base station, by means of which the voice signals from the terminal to the base station are transmitted via the access network element further to the public telephone network and vice versa. The subscriber network exponent is connected to the PBX using the V5.1 or V5.2 protocol.

Open interfaces (V5.1 and V5.2) between the access node and the telephone exchange 20 are defined in the ETS 300 324 and ETS 300 347 series standards of the European Telecommunications and Standard Institute. V5 connections allow subscribers in a physically separate access network, which may be wired or wireless, to be connected using a standard PBX interface. The dynamic hub interface V5.2 according to ETS 300 347-1 and 347-2 consists of one or more (1 to 16) PCM (Pulse Code Modulation) wires. One PCM cable 30 has a total of 32 channels each having a rate of 64 kbit / s, or 2048 kbit / s in total. The V5.2 interface supports analog telephones in the public telephone network, digital, such as ISDN (Integrated Services Digital Network) basic and system interfaces, and 35 other analog or digital semi-fixed terminal devices.

103370 2

In the previously known system, the availability of the terminal is not known in the telephone exchange. In this case, the call set-up of the call terminating in the terminal operates so that the call control of the switching center 5 allocates a time slot from the V5 interface and notifies the access network element of the terminating call. The subscriber network element allocates resources for the call until the radio network management notifies the terminal that it is not heard. On the basis of the notification 10, the access node releases its reserved resources and notifies the telephone exchange that the call is barred. The telephone exchange then frees up its reserved V5 interface slot for others to use.

A problem with the above procedure is that transmitting call signals from a telephone exchange via a hub to a closed terminal terminates unnecessarily the capacity of the access network. In particular, the V5 interface between the telephone exchange and the subscriber network element allocates tur-20 Hahn time slot or slots for such call setup, since it is not known to the access network element only that the terminal in question is unavailable.

The object of the present invention is to eliminate the problem described above. In particular, it is an object of the present invention to provide a method for enhancing the utilization of available capacity of a V5 interface.

As regards the features of the present invention, reference is made to the claims.

In the method of the present invention, to maximize the available capacity of a V5 interface in a wireless local area network environment, at least one V5 interface slot is allocated from a telephone exchange to a terminal 35. Available capacity refers to the maximum capacity of the V5 interface, which means a certain number of time slots. The subscriber network 103370 3 comprises a subscriber network element, which is connected to the telephone exchange via a V5 interface, and a base station, which is connected to the access network element and which transmits the call signals between the access network element and the master device.

According to the invention, the method monitors the availability of a terminal in a telephone exchange and prevents a call to an inaccessible terminal in a telephone exchange. This effectively avoids the unnecessary allocation of time slots in a situation where it appears that the terminal is not switched on and incoming calls cannot be made. The terminal is reachable when calls can be forwarded to it. The monitoring is based on transmitting to the pu-15 call center the status information of the subscriber network element in the subscriber network element indicating the availability of the terminal connected to the subscriber port. Preferably, the t-wide port status information is updated in the telephone exchange simultaneously with the 20 subscriber port status update in the access node. The subscriber port status information is maintained and updated in accordance with V5 recommendations using the control protocol. The subscriber port status can be OPERATIONAL or BLOCKED; 25 mats. Further, preferably, the status of the subscriber port is updated to BLOCKED when the radio connection between the base station and the terminal is broken, i.e. when the terminal is outside the coverage area of the base station or when that radio connection for some other reason is broken.

30 Thus, the call manager may immediately release the time slot that may have been reserved for the terminal, i.e., if the terminal was in a call connection when the radio connection was lost.

In a preferred embodiment, information on the availability of 35 terminals is transmitted by the IMSI attach and IMSI detach functions of the terminal (IMSI, International Mobile Subscriber 103370 4).

Identity) described, for example, in the standards of the ETS 300 530 series. When the terminal is powered on, it initiates the IMSI attach function, which in practice follows the standard terminal location update procedure. Information that the terminal is operational is usually stored in binary form in the access node. The IMSI detach function is performed when the terminal is turned off. Here too, status-10 information is stored in the access node. In a subscriber network element, information about the status of the terminal is indicated by means of the subscriber port status information.

An advantage of the present invention over the prior art is that the invention can reduce the load on call control resources in both the local exchange and the access node. Further, the invention makes it possible to reduce the unnecessary allocation of time slots for a V5 interface between a telephone exchange and a subscriber network element, thereby freeing up time slots for other forwarded calls. A further advantage of the invention is that the status of the terminal can be better monitored by means of the IMSI -attach and -detach functions.

The invention will now be described, by way of example, with reference to the accompanying drawing, which schematically illustrates one of the wireless access network environments of the present invention.

The wireless space-30 network system shown in the drawing includes a subscriber network element 2.

The access node 2 functions as a hub between the exchange 3 and the terminal 5, connecting the subscriber to the exchange 3. The access node 2 is connected via a V5.2 interface 1 which handles 1-16 PCM (2 Mbit / s) PCM cords to the exchange 3 of the exchange. (ET, Exchange Terminal) (not shown), which provides the functions required for a V5 interface. Further, the system shown in the drawing includes a plurality of base stations 4a, 4b and 4c, each having a specific coverage area. In the system of the drawing, the connection between the terminal and the telephone exchange 5 is established in such a way that signals are transmitted between the base station 4a and the terminal 5 via radio communication and from the base station via wired connections to the access network element 2 and V5 interface 1 to the telephone exchange.

Referring still to the drawing, when the terminal device 5 is turned on, an IMSI attach function according to the above recommendations is performed between the network and the terminal device. By this action, the terminal 5 notifies the network that it is operational, allowing calls to be forwarded to the terminal. In the subscriber network element 2, the value of the subscriber port corresponding to the terminal 5 is updated to the value OPERATIONAL. At the same time, this subscriber port status information is also updated to the PBX 3 via the control protocol V5 interface 1 20 by updating the subscriber data stored on the V5 interface used by the PBX.

When the current terminal 5 is turned off, the terminal performs an IMSI detach 25 operation, for which the terminal does not wait for confirmation from the base station. By this action, the terminal 5 indicates that it is not operational, i.e. the terminal is inaccessible, whereby no calls can be forwarded to the terminal. Now the status of the subscriber port corresponding to 30 terminals is updated to BLOCKED. At the same time, said subscriber port status information is also updated to the PBX 3 via the V5 interface control protocol by updating the subscriber information stored in the V5 interface used by the subscriber port.

Further, in connection with call setup, the telephone exchange can first determine whether or not the terminal to which the call is being directed is operational by reading from the subscriber data of the V5 interface the status of the subscriber port of that terminal. This avoids the unnecessary allocation of time slots from the V5 interface 1 between the access network element 2 5 and the telephone exchange 3.

The invention is not limited to the above embodiment only, but many modifications are possible within the scope of the inventive idea defined by the claims.

10

Claims (9)

A method for maximizing a V5 interface (1) incident tapping capacity in a wireless subscriber network environment comprising a subscriber network element (2) connected to a telephone exchange (3) by a V5 interface, and a base station (4a, 4b, 4c), with the aid of which the subscriber network element and the terminal equipment (5) transmits call signals, wherein a method is reserved for at least one V5 interface time interval for a call directed from the telephone exchange to the terminal equipment, characterized in that: the proximity of the terminal equipment in the telephone exchange is observed; and a call directed to a terminal equipment that cannot be prevented from the telephone exchange. Method according to claim 1, characterized in that the status data of the subscriber port is transmitted to the telephone exchange (3), which shows the proximity of the terminal equipment (5) connected to the subscriber port. Method according to claim 2, characterized in that the status data of the subscriber port is communicated to the telephone exchange upon updating the status data of the subscriber port in the subscriber network element (2). Method according to any of the preceding patent claims 1-3, characterized in that the status data of the subscriber port is communicated to the telephone exchange (3) by updating the subscriber data of the V5 interface (1) registered in the telephone exchange. Method according to any of the preceding claims 1-4, characterized in that with the terminal equipment (5) an IMCI attach function is performed where the terminal equipment is switched on; and due to the IMSI attach feature, is updated as the subscriber port status data OPERATIONAL, which shows that the terminal equipment can nose; and the subscriber port status data is transmitted to the telephone exchange (3). Method according to any of the preceding claims 1-4, characterized in that with the terminal equipment (5) an IMSI detach function is performed where the terminal equipment is switched off; due to the IMSI detach function is updated as the subscriber port status data BLOCKED, which shows that the terminal equipment cannot be nose; and the subscriber port status data is transmitted to the telephone exchange (3). Method according to any of the preceding claims 1 - 6, characterized in that as the subscriber port status data is BLOCKED updated, the radio connection between the base station (4) and the terminal equipment (5) is broken. Method according to any of the preceding claims 1 - 7, characterized in that the status data of the subscriber port is communicated to the telephone exchange (3) by mediating a CONTROL protocol. Γ Method according to any of the preceding claims 1-8, characterized in that in the telephone exchange the status of the terminal equipment (5) is checked on the basis of the subscriber data of the V5 interface.