ation electronics for a while. The new cards being installed are software- upgradeable. If all goes well, the new standards will be implemented on the same phys- ical cards, and future 3G service improvements can be realized by remote software configuration without requiring a visit to each base station. 2 21.2.1 IP support As base station equipment providers innovate in their development of IP support, there are several different approaches to IP support that might be taken. The simplest model is to receive the IP packets for data, to packetize the voice into IP, and to run a single IP pipe back to the MSC. An alternative approach might be to install the equivalent of a digital subscriber line access multiplexer (DSLAM) at the base station and have the IP packet data separated from the voice stream, just as a DSLAM at a local office puts data from digital subscriber lines (DSL) onto the public packet data network (PPDN), reducing the load on the public switched telephone network (PSTN). However, a DSLAM would only be useful in cases where soft handoff was not being used for data, such as the shared supplemental data packet channel. A third approach might be to in- stall a TCP/IP router at each base station. Having a router at each base station would allow more precise management of packet transport over the air interface and the backhaul network, possibly reducing delay and jitter. Such a system would require de- fined QoS classes for voice and data over the air interface. 21.2.2 Smart antennas Adaptive phased arrays (described in Sec. 4.1.1), known as smart antennas, are an- other rapidly improving technology. In summer 2002, the CDMA Development Group (CDG) gave only one award for the annual 3G CDMA Industry Achievement Award, and it went to Sprint PCS and Nortel Networks for the development and testing of an innovative smart antenna. This antenna doubles capacity for cdmaOne cells without requiring any other changes to the cellular network or to cellular telephones. The an- tenna uses adaptive antenna beam se