IP access into their core networks. The system is unlicensed mobile access pdf invisible to the network as a whole.
Since the GAN system works over the internet, a UMA-capable handset can connect to their service provider from any location with internet access. This is particularly useful for travellers, who can connect to their provider’s GANC and make calls into their home service area from anywhere in the world. This is subject to the quality of the internet connection, however, and may not work well over limited bandwidth or long-latency connections. UMA was developed by a group of operator and vendor companies. The initial specifications were published on 2 September 2004.
Gb interfaces for 3GPP Release 6 and renamed the system to GAN. The specification, though, defined support for multimode handset operation. Wi-Fi handsets are supported in the standard. UMA devices were announced in the second half of 2008.
GERAN-preferred: uses cellular networks if available, otherwise the 802. GAN-only: uses only the 802. In all cases, the handset scans for GSM cells when it first turns on, to determine its location area. This allows the carrier to route the call to the nearest GANC, set the correct rate plan, and comply with existing roaming agreements. The GAN release 8 documentation describes these new capabilities. GAN allows carriers to add coverage using low cost 802.
Subscribers at home have very good coverage. GAN makes sense for network operators that also offer Internet services. Operators can leverage sales of one to promote the other, and can bill both to each customer. Some other operators also run networks of 802.
They can leverage these hotspots to create more capacity and provide better coverage in populous areas. The carrier does not pay for much of the service, the party who provides the Internet and Wi-Fi connection pays for a connection to the Internet, effectively paying the expensive part of routing calls from the subscriber. However, carriers typically do not pass on these savings in the form of lower bills to customers who use Wi-Fi for calls. The cheaper rates for 802. 11 use, coupled with better coverage at home, make more affordable and practical the use of cellphones instead of land lines. 11 eliminates expensive charges when roaming outside a carrier’s network. 11 into a service that uses a single number, a single handset, a single set of services and a single phone directory for all calls.
VOIP plus a data phone are dropped when leaving high-volume data coverage. UMA enabled handsets to take advantage of the service. How much this is a problem may vary based on which handset is used. This may take time for subscribers and require additional support to be provided. The service is based on pre-3GPP GAN standard technology. Jan 2007, it has used UMA over 802.