cribed in Sec. 21.2.1, we might be able to install the equivalent of a digital subscriber line access multiplexer (DSLAM) at the base station. In this way, the base station itself becomes an Internet Protocol (IP) node. Not only might this reduce back- haul transport costs, it also might reduce data service delay times because there are fewer links in the packet path. This idea may not make sense if the user terminal can hand off to another base sta- tion. Then we could have the extra administration of managing the flow of packets from one base station to another after a handoff is complete. Even if we manage hard hand- offs by clever use of IP address assignment, soft handoff could make such a scheme into an administrative nightmare. The third-generation (3G) code division multiple access (CDMA) standards provide for shared packet data channels deliberately designed to offer efficient data service for stationary subscribers who do not hand off anywhere. If there is a large enough com- munity of stationary data service subscribers to warrant the use of a shared-packet CDMA channel, then there also might be a good case for making the base station an IP node and siphoning those packets off into the PPDN without hauling them back to the MSC. There is no reason stationary data users need to send their packets through the MSC. The MSC can handle the call processing, signaling, and billing, while the local IP network handles the subscriber's data packet stream. Short message service (SMS) is being extended to form enhanced message service (EMS) and multimedia message service (MMS), as described in Sec. 20.5. MMS is de- signed to send audio and video information, cellular snapshots, to other wireless sub- scribers. While the signaling information for MMS messages should go through the usual channels of MSC and ANSI-41, a large image file can be sent through the IP network di- rectly from base station to base station. If the 3G subscriber community starts sending a large number of MMS images, then this could be a major s