4Motion Installation Manual, Ver.3.5 - Alvarion

Chapter 1 - IntroductionBTS Common Equipment1.2 BTS Common Equipment1.2.1 Outdoor Radio Unit (ODU)The outdoor unit (ODU) is a high-power, multi-carrier radio unit that connects to one or more externalantennas.The following ODU port configurations are available:Table 1-1: ODU Port ConfigurationsItem Description Interface Comments1x1 (1Rx by 1 Tx)One receive port, onetransmit portOne Tx/Rx interface4x2 (4Rx by 2Tx)Four receive ports, twotransmit portsTwo Tx/Rx interfaces2x2 (2Rx by 2Tx)Two receive ports, twotransmit portsTwo Tx/Rx interfacesFor Macro Outdoor BTSsFor ODU installation refer to “AU-ODU Installation” on page 122.1.2.2 Antenna1.2.3 GPSIn the 4Motion architecture, the antenna is approached as an independent element. This provides theoperator with the flexibility to select the antenna source according to its supplier policy. To ensure theavailability of antennas that complement the 4Motion solution, Alvarion works closely with severalantenna suppliers to ensure availability of antennas that comply with its requirements.Alvarion can provide recommended antenna specifications based on the required antennas types foradditional antenna vendors.For antenna installation refer to “Antenna Installation” on page 197.GPS is used to synchronize the air link frames of Intra-site and Inter-site located BTSs to ensure that in allBase Stations the air frame start at the same time, and that all Base Stations switch from transmit(downlink) to receive (uplink) at the same time. This synchronization is necessary to prevent Intra-siteand Inter-site interference and Base stations saturation (assuming that all Base Stations are operatingwith the same frame size and with the same DL/UL ratio).For GPS Installation refer to “GPS Installation” on page 205.4Motion Installation Manual5