Multiplex communications – Communication over free space – Combining or distributing information via time channels
Patent
1997-11-04
2000-09-12
Kizou, Hassan
Multiplex communications
Communication over free space
Combining or distributing information via time channels
370278, 370277, 380 23, 713200, H04J 324, H04K 102, G06F 1300
Patent
active
061187755
DESCRIPTION:
BRIEF SUMMARY
The invention relates to improving the security of packet-mode data transmission in a mobile communication system.
FIG. 1 shows the parts of a cellular mobile communication system essential to the invention. Mobile Stations MS communicate with Base Transceiver Stations BTS over the air interface Um. The base stations are controlled by Base Station Controllers BSC associated with Mobile Switching Centres MSC. A subsystem administered by a base station controller BSC--including the base stations BTS controlled by it--is commonly called a Base Station Subsystem BSS. The interface between a centre MSC and a base station subsystem BSS is called the A-interface. The section of the A-interface on the side of the mobile services switching centre MSC is called a Network Subsystem NSS. Correspondingly, the interface between a base station controller BSC and a base station BTS is called the Abis-interface. A mobile services switching centre MSC switches incoming and outgoing calls. It performs similar tasks as the centre of a public telephone network PSTN. Additionally, it performs tasks characteristic of mobile telecommunication only, such as subscriber location administration, in co-operation with network subscriber registers (not separately shown in FIG. 1).
A typical radio connection used in digital mobile communication systems is circuit switched, i.e. the radio resources reserved for a subscriber are kept reserved for that connection during the whole call. General Packet Radio Service GPRS is a new service designed for digital mobile communication systems, such as the GSM system. The packet radio service has been described in the ETSI recommendation TC-TR-GSM 01.60. A packet-mode radio connection with effective utilization of radio resources can be offered to a user of a mobile station MS by means of the packet radio service. In a packet switched connection resources are reserved only when there is speech or data to be transmitted. The speech or data is assembled into packets with a given length. Such a packet having been transmitted over the air interface Um, and the transmitting party having no immediately succeeding packets to be transmitted, the radio resource can be released to the use of other subscribers.
In order to illustrate the description, but not to limit the invention, it is assumed that the system comprises a separate GPRS service control node, or a GPRS Support Node GSN, which controls the operation of the packet data service on the network side. This control comprises e.g. mobile station Logon and Logoff, mobile station location updates, and routing of data packets to the right destination. As regards the present application, the term "data", widely interpreted, refers to any information exchanged in a digital mobile communication system, such as speech coded in digital form, data transmission between computers, or telefax data. A GSN node can be situated in connection with a base station BTS, a base station controller BSC or a mobile services switching centre MSC, or apart from these. The interface between a GSN node and a base station controller BSC is called the Gb-interface.
Referring to FIG. 1 and 2, information, such as control signalling and user data, is exchanged between a mobile station and a GSN node by means of GPRS frames. Each Frame F comprises at least a header 1 and a data portion 2. In order for the system to know which mobile station has transmitted the frame, the header 1 comprises an identifier for the mobile station, e.g. a Temporary Logical Link Identity TLLI. At the beginning of a connection, the GSN node assigns to a mobile station a TLLI to be used during a GPRS connection. After the GPRS connection, the same TLLI can be reassigned to another mobile station.
In addition to a TLLI, a Network Layer Service access point Identity NLSI can also be used in the header 1 to indicate the application protocol used by the mobile station.
The data portion 2 comprises confidential information, e.g. user data or control messages. This kind of information has to be protected in order
REFERENCES:
patent: 5455863 (1995-10-01), Brown et al.
patent: 5742611 (1998-04-01), Brandin
patent: 5794139 (1998-08-01), Mizikovsky et al.
patent: 5864299 (1999-01-01), Nelms et al.
"Requirement Specification of General Packets Radio Service", GPRS REQUIREMENTS SPECIFICATION TG-GPRS#5/947 Helsinki, Nov. 94, Subject=GSM Phase 2+Work Item General Packet Radio Service (GPRS) pp. 1-33.
Kari Hannu
Karppanen Arto
Kizou Hassan
Nokia Telecommunications Oy
Tsegaye Saba
LandOfFree
Security of packet-mode transmission in a mobile communication s does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Security of packet-mode transmission in a mobile communication s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Security of packet-mode transmission in a mobile communication s will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-102476