Search results
Results From The WOW.Com Content Network
In Fixed Channel Allocation or Fixed Channel Assignment (FCA) each cell is given a predetermined set of frequency channels. FCA requires manual frequency planning, which is an arduous task in time-division multiple access (TDMA) and frequency-division multiple access (FDMA) based systems since such systems are highly sensitive to co-channel interference from nearby cells that are reusing the ...
For this reason, an entire time slot has to be dedicated to mobiles attempting to contact the network; this is known as the random-access channel (RACH) in GSM. The mobile transmits at the beginning of the time slot as received from the network. If the mobile is near the base station, the propagation delay is short and the initiation can succeed.
The UMTS channels are communication channels used by third generation (3G) wireless Universal Mobile Telecommunications System (UMTS) networks. [ 1 ] [ 2 ] [ 3 ] UMTS channels can be divided into three levels:
Demand Assigned Multiple Access (DAMA) is a technology used to assign a channel to clients that do not need to use it constantly. DAMA systems assign communication channels based on news issued from user terminals to a network security system.
assignment (to assign) asignación (asignar) 指配 ... Land mobile 806–947 0.035 .33 Cellular AMPS 806–947 0.003 .33 Amateur Land mobile GPS 1200–1600 .23
Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel.
The assignment of sub-carriers to users may be changed dynamically, based on the current radio channel conditions and traffic load. Single-carrier FDMA (SC-FDMA), a.k.a. linearly-precoded OFDMA (LP-OFDMA), is based on single-carrier frequency-domain-equalization (SC-FDE).
Frequency-division multiple access (FDMA) is a channel access method used in some multiple-access protocols. FDMA allows multiple users to send data through a single communication channel, such as a coaxial cable or microwave beam, by dividing the bandwidth of the channel into separate non-overlapping frequency sub-channels and allocating each sub-channel to a separate user.