Area restricted radio communication system

Abstract: In a radio based broadband system which in all essentials is based on battery-powered terminals there are restrictions which results in that the user cannot always be connected to the network. One restriction is when the network only has coverage within a certain, restricted geographical area. Another restriction is when the user shall save battery capacity and therefore only connects to the network when it is necessary. The technical problem the invention relates to therefore is to produce a device and a method which provides an extended paging functionality via a digital broadband radio system which is based on LMDS. The solution is briefly characterized in that one makes use of GSM as paging channel for an LMDS-based radio system, by means of which a nation-wide paging procedure is achieved.

Description: FIELD OF THE INVENTION The present invention relates to an area restricted digital radio based broadband system and a method according to the preambles of claims 1 and 4 respectively. PRIOR ART A system of the above mentioned kind is previously known from WO 95/26113. In a radio based broadband system which in all essentials is based on battery-powered terminals there are restrictions which leads to that the user not always can be connected to the network. One restriction is when the network only has coverage within a certain restricted geographical area, such as for instance city centres, air terminals, exhibition halls etc. Another restriction can be that the user wants to save battery capacity and therefore only connects himself/herself to the network when necessary. A mobile telecommunications system having a battery-powered telecomputer is described in WO 94/15431. The problem which the invention intends to solve consequently is to attend to that these terminals in an area restricted radio based broadband system can be accessed when they are outside the geographical area for which they have coverage, and that they also can be accessed when the are switched off. SUMMARY OF THE INVENTION The above mentioned problem is solved by a system according to claim 1 and a method according to claim 4. Thus in the present invention a global paging channel is utilized to contact said portable terminals when broadband sessions intended for said terminals exist in said area restricted digital radio based broadband system. One advantage with this is of course that when a terminal is outside the area for which it has coverage, the terminal is informed directly via the paging channel when a session intended for said terminal exists, at which said terminal can be moved to a coverage area for connection of the session. The terminal also need not all the time be connected to the battery demanding broadband network, but can be connected when necessary when a session exists, which in the same way as above is informed about via the paging channel. Further characteristics of the invention are given in the subclaims. DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION The embodiment relates to a nation-wide covering GSM paging functionality for a broadband radion system based on LMDS (Local Multipoint Distribution Services). By using GSM as paging channel for an LMDS-based broadband radio system, a nation-wide covering paging procedure is achieved. There are two typical cases of paging (in both cases the GSM-receiver is supposed to be switched on) : 1. The user of the terminal is within the coverage of the broadband radio system: If the terminal is switched on, it performs a random access and connects to the broadband network. After that it responds to the paging request and connects the session. If the terminal is not switched on, one gets the same type of notification as at a conventional SMS (Short Message Service). After that the user switches on his/her terminal which then connects according to the previous point. 2. The user of the terminal is outside the areas for which the broadband radio system has coverage: The terminal answers via SMS that it is outside the coverage area. The terminal connects by GSM' data service, at which the user can inform when he/she can be within an area where broadband coverage exists. In certain cases also the session can be performed by GSM's narrow band data transmission. In a radio based broadband system based on battery-powered laptops there will be two reasons for not being connected to the network: 1. The network only has coverage within certain "islands", for instance city centres, air terminals, exhibition halls. 2. In order to save battery one connects to the network only when necessary. Also in this type of network there is the need to be accessed, i.e. paging is desirable. What is said above is only to be regarded as an advantageous embodiment of the invention, and the scope of protection of the invention is only defined of what is indicated in the following patent claims.

Claims: An area restricted digital radio based broadband system including a broadband network and at least one portable terminal, said system being adapted to utilise a global paging channel to contact said terminal in response to the occurrence of broadband sessions intended for said terminal in said area restricted system, characterized in that said terminal includes a GSM-receiver activated at all time and said paging channel is a GSM-channel, and in that said terminal is adapted, when a user of said terminal is within the coverage area of said system and the terminal is switched on, to perform a random access operation and connect to said broadband network to establish a broadband session connection, and in that means are provided to transmit, if said terminal is switched off, a SMS notification to said GSM receiver to turn on said terminal, and in that , when said terminal is outside the coverage area of said system, said GSM-receiver is arranged to answer via SMS and inform that it is outside the coverage area, said terminal being arranged to establish connection by GSM's data service. The system according to claims 1, characterized in that said system is an LMDS. The system according to claim 1 or 2, characterized in that said terminal is a battery-powered laptop. A method of utilising a global paging channel to contact at least one portable terminal of an area restricted digital radio based broadband system in response to the occurrence of broadband sessions in said area restricted system intended for said terminal, characterized by , if a user of said terminal is within the coverage area for said area restricted system and said terminal is switched on, the following steps: a) a random access operation is performed by said terminal, b) the terminal is connected to said area restricted system, c) the terminal replies to the paging request and establishes a broadband session connection; and if the terminal is not switched on, a GSM-receiver included in said terminal and intended for the paging channel, receives a notification according to SMS, after which the user switches on said terminal and steps a) - c) above are performed establishing a broadband session connection, and, if a user of said terminal is outside the coverage area for said area restricted system, said GSM-receiver answers via SMS that it is outside said coverage area, and the terminal establishes connection by GSM's data service, after which said user informs when he/she can be within said coverage area for establishing connection of said session, said paging channel consisting of a GSM-channel and said area restricted system being an LMDS.

Inventors: LARSSON ROGER, OEHMAN HANS, LARSSON, ROGER, OEHMAN, HANS, Öhman, Hans
Applicants: TELIA AB
Application year: 1997
Main classification: H04Q7
IPC codes: H04W68