公开(公告)号：EP0824813A1

公开(公告)日：1998-02-25

申请号：EP97906195.0

申请日：1997-03-03

申请人： NOKIA TELECOMMUNICATIONS OY

发明人： KARI, Hannu ,  KARPPANEN, Arto

IPC分类号： H04L9 ,  H04L29 ,  H04W12

CPC分类号： H04L63/0428 ,  H04L63/12 ,  H04W12/02

摘要： In General Packet Radio Service GPRS, the data are coded into frames (F) with a given length and comprising a header (1) and a data portion (2). An intruder can interfere with GPRS communication by transmitting unauthorized copies of transmitted messages, or sending false messages and interfere with communication integrity. The reliability of GPRS communication is improved by modifying the frame (F) used on a GPRS connection so that possible extra copies of the frames can be revealed. This can be achieved e.g. by adding an extra information field (3) to the data portion (2) of a GPRS frame (F), the contents of the field being modified between two frames (F). The contents of the extra information field (3) can include the identity of the frame (F), the TLLI of the connection, the IMSI or MSISDN of the mobile station, or an identity formed by an algorithm generating pseudo-random numbers. A second extra information field (4) can be added to the data portion (2) of the frame (F), the field being preferably formed by a different algorithm than the first extra information field (3).

公开(公告)号：EP0804845A2

公开(公告)日：1997-11-05

申请号：EP96900337.0

申请日：1996-01-08

申请人： Nokia Telecommunications Oy

发明人： HÄMÄLÄINEN, Jari ,  KARI, Hannu, H. ,  KARPPANEN, Arto

IPC分类号： H04L12 ,  H04L29 ,  H04W76 ,  H04W88 ,  H04W92

CPC分类号： H04L69/169 ,  H04L29/06 ,  H04L69/16 ,  H04L69/168 ,  H04L2212/00 ,  H04W76/20 ,  H04W88/16 ,  H04W92/02

摘要： PCT No. PCT/FI96/00020 Sec. 371 Date Sep. 18, 1997 Sec. 102(e) Date Sep. 18, 1997 PCT Filed Jan. 8, 1996 PCT Pub. No. WO96/21984 PCT Pub. Date Jul. 18, 1996A packet radio system encapsulates data packets of external data networks by a point-to-point protocol PPP (FIGS. 4A, 4B), and passes them through one or more sub-networks to a point which supports the protocol of the encapsulated data packet. In addition, a special radio link protocol of the packet radio network is required on the radio interface between a mobile data terminal equipment and a support node. PPP packets are encapsulated in data packets of said radio link protocol. The disadvantage of the arrangement is that the data packets of both the PPP protocol and the radio link protocol contain protocol-specific fields, which reduces the transmission capacity of user information. Therefore, a PPP packet is compressed (FIG. 4C) before the encapsulation (FIG. 4D) by removing therefrom the unnecessary control fields. After having been transferred over the radio interface, the PPP packet is decompresssed into its original format (FIGS. 4F, 4G).

公开(公告)号：EP0666011A1

公开(公告)日：1995-08-09

申请号：EP94924325.0

申请日：1994-08-19

申请人： NOKIA TELECOMMUNICATIONS OY

发明人： KARPPANEN, Arto ,  TALARMO, Reino ,  TUOHINO, Markku

IPC分类号： H04W8

CPC分类号： H04W8/02

摘要： A method and an arrangement for subscriber location management among a group of radio networks comprising at least two radio networks (101, PMR1, PMR2) in which at least some of the subscribers (SBR1, SBR2, SBR3) may roam away from the home network and register in another radio network over the radio path. To enable centralized subscriber location management, the subscriber database (HLR) of one radio network (101) is arranged to maintain in a centralized manner the location data of all subscribers (SBR1) that have roamed outside their home networks and registered in another radio network (PMR2) at least with an accuracy of a radio network.