ce (OTD) measurement of signals from multiple BTSs. These measurements fall into one of two categories that is, location measurements specific to one MS used to compute the location of this MS and assistance measurements specific to all MSs in a certain geographic area. All location and assistance measurements obtained by an LMU are supplied to a particular SMLC associated with the LMU. The instructions concerning the timing, the nature and any periodicity of these measurements are either provided by the SMLC or are pre-administered in the LMU. There are two types of LMU namely Type A LMU which is accessed over the normal GSM air interface and Type B LMU is accessed over the Abis interface. LCS Client: LCS client is a logical functional entity that requests from the LCS server in the PLMN location information for one or more than one target MS within a specified set of parameters such as QoS. The LCS Client may reside in an entity (including the MS) within the PLMN or in an entity external to the PLMN. LCF is the functional component of the LCS client. LCS Server: LCS Server is a software and/or hardware entity offering LCS capabilities. The LCS Server accepts requests, services requests, and sends back responses to the received requests. The LCS server consists of multiple components, which are distributed to one or more PLMN and/or service provider. Table 9.6 shows the allocation of LCS components to network elements. These components are Subscriber Handling component, System Handling component, Client Handling component and Positioning componet. The system handling components include LMMF, LSCF, LSBF, LSBcF, and LCCTF. LSAF and LSPF are subscriber components whereas PRAF, PRCF, PCF, PSMF, and PRRM are positioning components. The client component includes LCCF, LCAF and LCZTF. The details of LCS functional components can be found in [38,39]. Another key element is Cell Broadcast Center (CBC) which is associated with a BSC and also with SMLC. The SMLC interfaces with CBC in order to broadcast assistance data usi