CTV(Chinese Translation Version),中文譯稱。一段中文或英文的簡短說明:-:知識分類。====================================================
LAPDm(Link Access Procedure on the Dm channel),Dm通道鏈路接取程序。其中"m"表示modification(或mobile?)。
The concepts, terminology, overview description of LAPDm functions and procedures, and the relationship with other Technical Specifications are described in general terms in 3GPP TS 04.05.
The frame formats defined for LAPDm are based on those defined for LAPD. However, there are important differencesbetween LAPDm and LAPD, in particular with regard to frame delimitation methods and transparency mechanisms. These differences are necessary for operation within the constraints set by the radio path.
LAPDm supports two modes of operation:
- unacknowledged operation using UI frames;
- acknowledged operation using the multiple frame procedure.
As a choice of implementation, the two modes of operation may be implemented independently of each other. This ispossible since there is no interactions between the two modes, other than queuing at the transmitter, even when theycoexist on the same physical channel.
For BCCHs and CCCHs only the unacknowledged mode of operation needs to be implemented. LAPDm is used for information sent on the control channels BCCH, AGCH, NCH, PCH, FACCH, SACCH and SDCCH as defined in 3GPP TS 04.03.
說明: AGCH, NCH and PCH are sometimes referred to by the collective name CCCH and FACCH, SACCHand SDCCH are, similarly, referred to by the collective name DCCH. LAPDm may also be used on other types of channel.:-:GSM Um界面L2堆疊名稱。

[-] 3GPP TS 04.05: "Data Link (DL) layer General aspects"
[-] ETSI TS 100 938 V8.2.1 (2002-05) Technical Specification Digital cellular telecommunications system (Phase 2+); Mobile Station - Base Stations System (MS - BSS) Interface Data Link (DL) Layer Specification (3GPP TS 04.06 version 8.2.1 Release 1999)

LAPG(Link Access Procedure on the G-channel),在GPRS通道上的鏈路接取程序。是GPRS-LLC通信協定的舊稱,目前正式文件已經很少使用此名稱。:-:GPRS/L2信令名稱。

LCS(Location Services),定位服務。

LLC(Logical Link Control),邏輯鏈路控制協定。對應於ISO OSI模型第2層,LLC的主要功能是在MS與SGSN之間轉運(convey)第3層訊息-SNDCP。LLC的挑戰在於能夠同時支援許多MS使用SGSN,以及對相同MS來說,能夠服務許多不同第3層單體(entity)的訊息。
LLC在1998年的舊稱為LAPG(Link Access Procedure on the G-channel):-:GPRS在MS-SGSN間特有的堆疊。

- the provision of one or more logical link connections discriminated between by means of a D-LCI;
- sequence control, to maintain the sequential order of frames across a logical link connection;
- detection of transmission, format and operational errors on a logical link connection;
- recovery from detected transmission, format, and operational errors;- notification of unrecoverable errors;
- flow control; and
- ciphering.

[-] Digital cellular telecommunications system (Phase 2+);Mobile Station - Serving GPRS Support Node (MS-SGSN);Logical Link Control (LLC) Layer Specification(3GPP TS 44.064 version 6.2.0 Release 6) 

LOS(Line of Sight),目視線。用在無線通信領域,當兩個天線之間,可以用一條想像中的光線連接起來,其過程不被任何障礙物阻擋,這種情況稱為LOS連接。以此類推,non LOS就是非目視線,指兩天線間的LOS上障礙物很多,無法完成LOS傳輸;near LOS是指在LOS上面雖有障礙物,但是障礙物可能不大,以致於天線間的無線波束的能量還是可以藉由LOS傳輸。:-:無線傳輸術語。