
Chapter 10
specifications. The 3GPP working group TSG CT W63 is charged with “Interworking with
External Networks.” Early specifications from this group list IETF dependencies but not IEEE
dependencies. However, this situation may change as IEEE 802.21 gains momentum. Another
organization, Unlicensed Mobile Access (UMA), which was started in 2004, gained an early
prominent role in the area of accessing GSM/GPRS services over unlicensed spectrum
technologies such as 802.11. While the term UMA is still seen frequently in the literature, the
work of this group was fully transferred to 3GPP in 2005. We will discuss how UMA is used
as a transitional technology ...