This Global System for Mobile communications Technical Specification ( GTS) identifies the interworking functions and requirements to support Packet Assembly/Disassembly (PAD) services in the PLMN. GSM 09.05 applies to PAD access in order to provide communications wit h host systems connected to Packet Switched Public Data Network (PSPDN ) for Mobile Stations (MS)s. Within this GTS, the requirements for accessing an existing PAD in a P SPDN (basic PAD access) or accessing a dedicated PAD are considered se parately. In each case, the general problem of charging is examined. This GTS considers only the access by a MS to a PAD and not the revers e access (i.e. only mobile originated calls are supported).