uropean regulations. Dynamic Routing: In contrast to static routing (q.v.), dynamic routing is the process whereby routers continuously update and exchange routing information in order to automatically adjust to changes in network topology. Equivalent Isotropic Radiated Power (EIRP): EIRP measures the total effective transmitted power of a radio, including antenna gain and any cable Chapter Sixteen and connector losses between transmitter and antenna. A 100 mW (20 dBm) transmitter with a 4 dB antenna and 1 dB of losses will have an EIRP of 200 mW (23 dBm). Ethernet: Ethernet is the predominant wired networking technology, developed at the Xerox Palo Alto Research Centre in the 1970s and standardised in the IEEE 802.3 specification. Ethernet types are designated a ABase-B, where A specifies the data rate, now up to 10 Gbps, and B specifies the cabling type, examples being T for twisted pair copper cabling and SX for LED powered multi-mode optical fibre. Extended Unique Identifier: An IEEE alternative to MAC addresses, extended in length from 48-bit to 64-bit addresses in EUI-64. Fading: Fading or multipath interference occurs when a primary signal combines with delayed signals, typically caused by reflection or refraction from objects on or near the line-of-sight, resulting in constructive or destructive (fading) interference or phase shifts. Fading can be identified and corrected by techniques such as the use of pilot tones in OFDM radios. Firewall: A firewall is a software component that controls the external interfaces of a network and restricts or blocks certain types of traffic or activity. Firewalls are essential for network security, and careful configura- tion is essential to ensure correct operation and to avoid unintended interruption of authorised network traffic. Forward Error Correction: Forward error correction (FEC) is a method of reducing bit errors during data transmissions. Redundant bits, each usu- ally a complex function of many bits from the input data stream, are added to the transmitted data