is subject to the Terms of Use as given at the website. Access Technologies Chapter 6 Under the standards, CableLabs crafted an original cable modem certification standard called DOCSIS 1.0 which guarantees that modems carrying the certification will interoperate with any headend equipment, are ready to be sold in the retail market, and will interop- erate with other certified cable modems. Engineers from Askey, Broad- com, Cisco Systems, Ericsson, General Instrument, Motorola, Philips, 3Com, Panasonic, Digital Furnace, Thomson, Terayon, Toshiba, and Com21 participated in the development effort. The DOCSIS 1.1 specification was released in April 1999, and included two additional functional descriptions, which began to be imple- mented in 2000. The first specification details procedures for guaranteed bandwidth, as well as a specification for quality of service guarantees. The second specification is called Baseline Privacy Interface Plus (BPI+); it enhances the current security capability of the DOCSIS stan- dards through the addition of digital certificate-based authentication and support for multicast services to customers. DOCSISTM 2.0 In December 2002 the ITU-T announced the approval of a standard defining the second-generation data over cable system, known as DOCSIS 2.0. ITU recommendation J.122 gives cable operators the ability to offer speeds up to 600 times faster than a standard dial-up telephone modem provides. The new standard can be used as the foundation upon which IP-based telephony services can be offered. The enhancements that J.122 provides over its predecessor are pri- marily focused on the upstream transmission path from the customer to the network. Changes include increased capacity and improved robust- ness over the upstream path. While the DOCSIS name is in widespread use, CableLabs now refers to the overall effort as the CableLabs Certified Cable Modem Project. Wireless Access Technologies To understand wireless communications it is necessary to examine both radio and telephone technologies