gnals Sent Over Existing House Wiring Thermostat Mini-Timer Controller Wall Switch Video Surveillance Lamp Module Appliance Module Systems Module Figure 12.14 A control network dard household AC powerline wiring (with off, on, and dim functions). X10 Ltd. publishes the specifications, manufacturers can embed the trans- mitters into their appliances, and X10 Ltd. manufactures and sells the receiving and control devices. CEBus-CEBus, as discussed earlier in this chapter, is an open standard that specifies the technology and parameters for communications using powerlines, Cat 5 twisted-pair, coax, wireless, and infrared. It is based on EIA 600. Advantages of control networks include the fact that there are existing product solutions and well-established industry standards. Control networks also have rela- tively low cost and simple implementation. The disadvantage is that these networks are not designed to support real-time, high-bandwidth, or mobility requirements, SO the value proposition of standalone applications does not offer the incentives for the mainstream market to consume the products. Wired HANs Wired HANs include Universal Serial Bus (USB), Category 5 or 10BASE-T wiring, and IEEE 1394 (FireWire). The benefits of wired HANs are that wired network standards are reliable and robust. The drawbacks of wired networks are that Chapter 12 Broadband Access Alternatives penetrating the mass market requires a "no new wires" technology. These solu- tions, therefore, will primarily extend only to new homes that are making use structured wiring and perhaps to the technophile hobbyist and professional home user market. HAN Gateways and Servers A HAN requires a system for identifying data and routing it to its destination, and this implies the need for gateways and servers. A residential gateway connects a HAN to the Internet. A hardware device similar in appearance to a router, it pro- vides many features necessary in a HAN. Most residential gateways support at least the basic features of broadband connectivity (usual