A mobile ISDN protocol architecture

The author proposes a mobile ISDN (integrated services digital network) protocol architecture, which is capable of supporting packet communication services. Connections in layers two and three for transporting user packet data are defined between a mobile terminal and a packet handler (PH) by means of a cell site and a switching function, which is installed between the cell site and the PH. This architecture enables packet data loss, which has occurred during handoff, can be recovered after the mobile terminal retunes to a radio channel, using the existing layer two-packet recovery procedure. No matter how many times communication path changeovers are required, the mobile terminal can continuously communicate with the originally connected PH. It is shown that handoff does not affect the existing layer two and higher layer protocols and that the same handoff procedure can be used for both packet- and circuit-switched communications