all nodes are connected to the network simultaneously), one of the first technical challenges faced in the implementation of packet radio networks was a means to control access to a shared communication channel to avoid collisions of signals. Professor Norman Abramson of the University of Hawaii led development of a packet radio network known as ALOHAnet and performed a number of experiments beginning in the 1970s to develop methods to arbitrate access to a shared radio channel by network nodes. This system operated on UHF frequencies at 9,600 baud. From this work the Aloha multiple access protocol was derived. Subsequent enhancements in channel access techniques made by Leonard Kleinrock et al. in 1975 would lead Robert Metcalfe to use carrier-sense multiple access (CSMA) protocols in the design of the now commonplace Ethernet local area network (LAN) technology. Over 1973–76, DARPA created a packet radio network called PRNET in the San Francisco Bay area and conducted a series of experiments with SRI to verify the use of ARPANET (a precursor to the Internet) communications protocols (later known as IP) over packet radio links between mobile and fixed network nodes. This system was quite advanced, as it made use of direct sequence spread spectrum (DSSS) modulation and forward error correction (FEC) techniques to provide 100 kbit/s and 400 kbit/s data channels. These experiments were generally considered to be successful, and also marked the first demonstration of Internetworking, as in these experiments data was routed between the ARPANET, PRNET, and SATNET (a satellite packet radio network) networks. Throughout the 1970s and 1980s, DARPA operated a number of terrestrial and satellite packet radio networks connected to the ARPANET at various military and government installations. Amateur Packet Radio and the AMPRNet Amateur radio operators began experimenting with packet radio in 1978, when—after obtaining authorization from the Canadian government—Robert Rouleau, VE2PY; Bram Frank, VE2BFH; Norm Pearl, VE2BQS; and Jacques Orsali, VE2EHP of the Montreal Amateur Radio Club Montreal, Quebec began experimenting with transmitting ASCII encoded data over VHF amateur radio frequencies using homebuilt equipment. In 1980, Doug Lockhart VE7APU, and the Vancouver Area Digital Communications Group (VADCG) in Vancouver, British Columbia began producing standardized equipment (Terminal Node Controllers) in quantity for use in amateur packet radio networks. In 2003, Rouleau was inducted into CQ Amateur Radio magazine's hall of fame for his work on the Montreal Protocol in 1978. Not long after this activity began in