Specifications

Radio Link Communications Model
Radio Frequency Channel Types
August 08, 2000 68P81095E55-E B-5
Network Layer
The network layer is controls how packets are routed from source to destination.
Routing functions are controlled by the DAC, BSC and the DAP within the network
and are not part of the Radio Link. The L3 Control portion of the link is a subset of
the GSM A-bis complaint Mobis protocol. These aspects are responsible for tasks
like Call Control and Mobility Management. Call Control Functions are controlled
by the interaction of the MS and the EBTS.
Transport Layer
The basic function of the transport layer is to accept data from the session layer and
split it up into smaller units if needed. This function is controlled by the DAC, BSC
and the DAP within the network and is not part of the Radio Link.
Session Layer
The session layer allows users on different machines to login and initiate multiple
applications. Since the radio link is peer-to-peer, The ability to multiplex on-air is
not a requirement so the session layer does not apply to the radio link.
Presentation Layer
In the Radio Link environment, the application layer is the voice compression and
decompression algorithm on the MS and the XCDR that creates the required data
packets for on-air transmission. The compression algorithm used is VSELP.
Application Layer
In the iDEN system model the application layer is the Mobile transducers (speaker
and microphone) and the resultant sounds that are produced or encoded.