Nokia Mobile Phones Limited

Nokia Corporation

Nokia Telecommunications Oy

Harri Hansen

Jukka Immonen

Hangkan Mitts

H&aring;kan Mitts

Frederic J Bauchot

Gerard Marmigere

Juha Ala-Laurila

Jorma Stenman

Juha Salvela

The security keys in the mobile terminals and access points of a wireless local area network (WLAN) are created, utilized and managed for a communication session between a mobile terminal and access point. Both the WLAN link level security protection and IP security functions of the network use the same Internet Key Exchange (IKE) key management protocol and use certificates in the same certificate hierarchy. When the mobile terminals associates with the network, it uses the IKE protocol with private keys and certificates to generate WLAN link level keys with the access point and provide mutual authentication.

Key management methods for wireless LANs

The invention relates generally to procedures facilitating the routing in a network-structured telecommunications network. In the network structure according to the invention, connections are established by using a predetermined partial group of connections forming a tree topology. Advantageously the number of said predetermined tree topologies is more than one, in which case the node starting the setup of the connection chooses the tree topology to be used in establishing the connection in question. Thus the advantages offered by the tree topology can be flexibly utilised in a network-structured telecommunications network.

Method for flexible use of a tree topology in a wireless ATM system

In a network structure according to the invention for realising a radio extension of an ATM network, only part of the switches of the ATM network are provided with functions required for supporting wireless terminals. In between these wireless-specific switches, there are provided individual connections in order to distribute control and management information. The wireless-specific switches and the individual connections therebetween form a parallel, tree-like PNNI node structure in relation to the rest of the ATM network, so that the wireless-specific switches belong, in addition to said PNNI node structure, also to the node structure of the regular ATM network. With a structure like this, the additions required by the support of wireless terminals in the PNNI protocol remain very slight.

Network structure for realizing part of a wireless ATM system and method for executing inter-switch handover in said network structure

Apparatus, and an associated method, for identifying whether a mobile terminal and access point of a WLAN (wireless local area network) are capable of operation pursuant to a proprietary communication mode. If a determination is made that the communication pair is capable of operation pursuant to the proprietary communication mode, the mobile terminal is instructed to operate pursuant to the proprietary communication mode. Handover procedures are also provided by which better to assure that ongoing communications, during and subsequent to handover shall also be effectuated pursuant to the proprietary communication mode. Improved communication quality when the communication pair is operated pursuant to the proprietary communication mode relative to operation pursuant to a conventional IEEE 802.11 communication mode is possible.

Apparatus, and associated method, for selectably operating radio device in alternate operating mode

A reference is made to ATM cells by dividing the cells into groups (31, 32, 33, 34) which are identified on the basis of a group-oriented serial number and/or on the basis of the combination of identifiers included in the cells of the group. In the latter case, the combination of the identifiers is compared with a given predefined aperiodic character string. A given cell within the group is identified on the basis of which cell it is counting from the beginning and/or from the end of the group, or on the basis of the identifier included in the cell.

Cell indication in the cell flow of an ATM system

In a radio data transmission system which transmits data in cell form, the risk of cell loss or the risk of out-of-ordering during handover can be diminished by synchronizing the cell transmission between the new (50) and the old (40) base stations. The old base station (40) delivers to the new base station (50) and/or the switch (51), information on the last cell that was transmitted successfully and in the right order through the old base station, whereby the new base station continues the transmission by starting from the first failed cell. Cells need not be identified one by one if group numbering is applied in which the first or the last cell of a given group (31, 32, 33, 34) or a given counter cell is numbered, and the rest can be indicated, where necessary, by counting the distance from the numbered cell.

Maintaining the composition of transferred data during handover

In a radio extension of an ATM network, prior to establishing a given connection the switch of a fixed network enquires access points as to what is the resource situation in said access points. After receiving responses the switch decides to which access point the connection is allocated. During handover, the resource enquiry is accomplished as a response to the handover request sent by the mobile terminal, which request is transmitted either when the connection to the old access point still operates or after the connection is closed; in the latter case, the request is retransmitted through the new access point.

Method for establishing radio connection as part of an ATM network

In the handover of a radio extension of an ATM network there are used markers that are located at fixed locations in the ATM cell stream in order to indicate the ending of an uplink and downlink cell stream, so that the switching of cell streams can be carried out in a synchronised fashion, and cells are not lost and their relative order does not change. If a downlink data transmission via the old access point succeeds, the old access point attaches to the last forwarded information field a notice of closing the traffic, in which case the mobile terminal transfers the information of successful transmission to the new access point. In another case, the old access point sends the unforwarded cells to the new access point and terminates the transaction with the same marker that generally indicates the end of a downlink cell stream.

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Espoo, Finland

Harri Hansen