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Multi-carrier code-division multiple access (MC-CDMA) is a multiple access scheme used in OFDM-based telecommunication systems, allowing the system to support multiple users at the same time over same frequency band. MC-CDMA spreads each user symbol in the frequency domain.
CDMA is analogous to the last example where people speaking the same language can understand each other, but other languages are perceived as noise and rejected. Similarly, in radio CDMA, each group of users is given a shared code. Many codes occupy the same channel, but only users associated with a particular code can communicate.
An advanced form of FDMA is the orthogonal frequency-division multiple access (OFDMA) scheme, for example, used in 4G cellular communication systems. In OFDMA, each node may use several sub-carriers, making it possible to provide different quality of service (different data rates) to different users.
cdmaOne network structure. The IS-95 standards describe an air interface, [1] a set of protocols used between mobile units and the network. IS-95 is widely described as a three-layer stack, where L1 corresponds to the physical layer, L2 refers to the Media Access Control (MAC) and Link-Access Control (LAC) sublayers, and L3 to the call-processing state machine.
DS-CDMA (Direct-Sequence Code Division Multiple Access) is a multiple access scheme based on DSSS, by spreading the signals from/to different users with different codes. It is the most widely used type of CDMA. Cordless phones operating in the 900 MHz, 2.4 GHz and 5.8 GHz bands; IEEE 802.11b 2.4 GHz Wi-Fi, and its predecessor 802.11-1999.
CDMA Certification Forum (known as CCF) was the original official authority governing CDMA Device certification.The CCF was an international partnership between network operator and device vendors [1] to maintain and evolve a core global device certification process that helps improve quality through consistent interoperability, conformance and performance testing across the globe.
On Dec. 6, the family received a phone call from immigration authorities and they were told to report to an office in Greenspoint, Texas, four days later to discuss Salazar-Hinojosa's case ...
CDG – CDMA Development Group CDMA – Code Division Multiple Access CDR – Call Detail Record Cell site. CIBER – Cellular Intercarrier Billing Exchange Roamer Cibernet. CHAP – Challenge- Handshake Authentication Protocol aka (HDR – High Data Rate) Clearing. Clearinghouse. CLI – Calling Line Identification – See Caller ID