ABSTRACT
The growth of the HSPD networks has made it even more desirable to offer a voice service using VoIP together with data to support highly diversified multimedia services. When HSPD and VoIP are deployed together, a separate circuit-switched network need not be dedicated for voice services. Besides, as most of the HSPD networks were designed using the most up-to-date technology, the spectral efficiency of wireless mobile VoIP networks can be greatly improved over that of packet data services designed for 3G voice networks. This makes the wireless mobile VoIP service attractive to service providers who face constraints on the availability of the frequency spectrum; they also have the advantage of operating an integrated network offering both voice and data services.
