ple access (CDMA): - A second-generation (2G) digital mobile phone technology that operates in the 800-MHz and 1.9-GHz PCS bands. Code division multiple access 2000 (CDMA 2000): - A CDMA version for third-generation (3G) networks. Competitive local exchange carrier (CLEC): - A local telephone carrier that was not one of the original Bell System operating companies. Constellation: - An array of satellites that is designed to provide continuous, or near-continuous, access from any point on earth. CRT: - See Cathode ray tube. Cybersecurity: - The protection of computers and networks. DARPA: - See Defense Advanced Research Projects Agency. Data hiding: - See Steganography. Defense Advanced Research Projects Agency (DARPA): - The central research and development organization for the U.S. Department of Defense (DoD). Dense wavelength division multiplexing (DWDM): - A higher capacity form of wavelength division multiplexing. Dielectric: - An insulator, such as glass or plastic. Digital radio: - A radio based on digital technology. Digital subscriber line (DSL): - High-speed Internet access service using phone lines. GLOSSARY Downlink: - A communications channel that sends audio and/or video from a satellite to earth. Downstream: - A communications channel that sends data from a satellite to earth. DSL: - See Digital subscriber line. DWDM: - See Dense wavelength division multiplexing. EDGE: - See Enhanced data rates for global evolution. Encryption: - The process of transforming plain information into a secure format, designed to protect its confidentiality. Enhanced Data Rates for Global Evolution (EDGE): - An enhancement to TDMA and GSM that boosts data speeds to 384,000 bits per second. ESA: - See European Space Agency. European Space Agency (ESA): - The organization that manages the European space program on behalf of 15 member states. Extensible Markup Language (XML): - An open standard for describing data that's used for defining data elements on a Web page and business-to- business documents. XML has become the st