rnet access, it is called BPL; simply put, it is the distribution of IP-based services over powerline infra- structure. In this case, a computer or other digital device only needs to plug a BPL modem into any outlet in a facility (home or building) equipped for high-speed Internet access. The most obvious advantage of BPL over DSL or cable modems is the extensive availability of power infrastructure; while not everyone has tele- phone lines or cable TV installed, most everyone does have power, so PLT enables more people in more locations to gain access to the Internet. On the other hand, the lack of standards for powerline as an access technology means that there is no standard provisioning of the service-there is no well-established process that can be repeated over and over. And of course, there are differences in the physical char- acteristics of the electricity network. There are also questions about the total band- width BPL can provide as compared to DSL or cable modems. Chapter 12 Broadband Access Alternatives BPL makes use of the electric circuit between the electric substations and home networks; one standard used for this application is ETSI PLT. PLT modems transmit in medium and high frequency-that is, the 1.6MHz to 30MHz electric carrier. The asymmetric speed in the modem is usually from 256Kbps to 7Mbps. The speed in the repeater, located in the meter room, is up to 45Mbps, and up to 256 PLT modems can be connected. In the medium-voltage stations, the speed from the headends to the Internet is up to 135Mbps. Utilities use either optical fiber or wireless links to connect to the Internet. In the access network, current technology can deliver speeds of up to 45Mbps, while in the home networking applications, up to 200Mbps is possible using the HomgPlug AV standard. (HAN technologies and powerline standards are explored at the end of this chapter.) QoS and CoS capabilities can be implemented by using PLT technologies, which is a critical feature in support of real-time and streaming media applications. 