h as addresses on one network, with quantities or values of another set, such as devices on a second network (e.g., name-address mapping, internet work-route mapping). mark The signal (communications channel state) that corresponds to a binary 1. marker A wired-logic control circuit that, among other functions, tests, selects, and estab- lishes paths through a switching state(s) in response to external signals. matrix (1) An arrangement of elements (numbers, characters, dots, diodes, wires, and so on) in perpendicular rows. (2) In switch technology, the portion of a switch architecture where input leads and output leads meet, any pair of which can be connected to establish a through circuit. Also called a switching matrix. MAU (media attachment unit) A transceiver that connects to the AUI port of an Ethernet interface card and provides attachments to some type of data communications medium. MB (megabyte) 1,048,576 bytes; usually referred to as 1 million bytes. MB-OFDM (Multiband OFDM) A UWB standard that transmits data simultaneously over multiple, accurately spaced carrier frequencies and features high spectral flexibility as well as resilience to RFI and multipath. mbone (multicast backbone) A virtual network on top of the Internet that supports rout- ing of IP multicast packets, intended for multipoint multimedia transmission. With mbone, a single packet can have multiple destinations and is replicated only at the closest node before the final receiver. This means that it can pass through several routers before it needs to be replicated to reach its final destinations. This leads to much more efficient transmission and also ensures that packets reach multiple destinations at roughly the same time. Mbps (megabits per second) 1,048,576 bits per second; usually referred to as 1 million bits per second. MBS (mobile broadband services) Very high-bit-rate services (over 100Mbps) over wire- less channels. MCML (Multi-Class Multi-Link) PPP A protocol that makes it possible to have multiple classes of latency-sensitive