 HELLO, or other IGPs, and to advertise routes to another autonomous system using the EGP. Gateway-to-Gateway Protocol The original IGP used by Internet core gateways (i.e., by routers). GB (gigabyte) 1 billion bytes, or 1,000MB. Gen2 standard (UHF Generation 2 Air Interface Protocol) An EPCglobal standard that forms the backbone of RFID tag standards. GEO (geosynchronous orbit) A circular orbit with a 24-hour orbital period approximately 22,300 miles (36,000 km) above the earth's equator. Because satellites in this orbit appear sta- tionary relative to the earth's surface, GEO is especially useful for communications satellites that transmit to fixed earth stations. GERAN (GSM EDGE Radio Access Network) A second phase of EDGE that is planned to offer data rates of up to 1,920Kbps, to support packetized voice and real-time services. GERAN is a common evolution path for GSM and TDMA that intends to provide a cost-efficient means to deliver 3G services within the existing frequency bands GFP (Generic Framing Procedure) A protocol that allows mapping of variable-length, higher-layer client signals over transport networks such as SDH/SONET and OTN networks. GGSN (gateway GPRS support node) A device that acts as a gateway between the GPRS network and public data networks such as IP and X.25 networks. GGSNs also connect to other GPRS networks to facilitate GPRS roaming. GHz (gigahertz) 1 billion cycles per second. GigE (Gigabit Ethernet) An Ethernet standard that supports 1Gbps. Sometimes referred to as 1Gbps Ethernet. global information infrastructure A vision of individual national information infrastruc- tures joined together to form an international network. GMPLS (Generalized Multiprotocol Label Switching) An enhancement to MPLS technology that allows service providers to dynamically provision resources and provide the nec- essary redundancy for implementing various protection and restoration techniques for optical networks. GMSK (Gaussian Minimum-Shift Keying) A kind of continuous-phase frequency-shift keying modu