The scope of this document is to define the Packet Data Specification of the wideband air interface (WAI). The wideband air interface called Uw is the interface between the fixed network equipment (FNE) and the subscriber units, or directly between subscriber units in a wideband system. The general wideband system model is shown in Figure 1 below and illustrates the Radio to FNE Mode of operation. A Vehicular Repeater (VR) could additionally act as a relay between FS and MR when coverage limitations require the use of this local coverage area extension.

The Wideband Air Interface (WAI) reference point Uw is between the MRC and FNE, or MRC to MRC, and is used for wireless communications between these functional groups. OSI layers 1, 2, and 3 are the specified scope of the implementation of the Uw services. The PDS defines the lowest sub-layer of OSI layer 3 and directly interfaces with the LLC layer. This standard describes the services, protocol(s), and PDU formats used for the conveyance of IPv4 and IPv6 bearer service. This document specifies the operation of IPv4 or IPv6 in conjunction with the WAI in each of the three system configurations. The wideband data Sub-Network Dependent Convergence Protocol (SNDCP) is a robust protocol that conditionally resides between the WAI and the Internet Protocol. The functions allocated to the PDS layer include the following major aspects:

•IP Version 4 Datagram Mapping to SNDCP and LLC Primitives IP Version 6 Datagram Mapping to SNDCP and LLC Primitives

• SNDCP Context Management

• IP to WAI Address Management

• Supplemental IP Service Definition