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CDMA Handoff Defination,Types and Capacity

CDMA Handoff Defination,Types and Capacity Handoffs The TIA/EIA Interim Standard, Mobile Station – Base Station Compatibility Standard of Dual- Mode Wideband Spread Spectrum Cellular System (TIA/EIA/IS-95), states that a CDMA base station shall support three types of handoff processes. Which type of handoff used in cdma? CDMA to CDMA Hard Handoff A CDMA to CDMA … Read more

Forward Power Control in CDMA

Message Transmission Mode MS measures the frame quality and informs the base station to the result i.e. whether it is in the threshold or periodical  mode. Base station determines whether  to change the forward transmitting power or not. In IS-95 system, the forward power control is slow but in CDMA2000 system it is fast. Forward … Read more

What is Work of Paging Channel in CDMA?

What is Work of Paging Channel in CDMA?The Paging Channel in CDMA (Code Division Multiple Access) serves a crucial role in the efficient functioning of the communication system. As a dedicated control channel, the Paging Channel is responsible for transmitting important information, such as incoming calls and system messages, to mobile devices within a CDMA … Read more

Handoff Candidate Classification in CDMA

The mobile station continuously searches for Pilots to detect the presence of other CDMA signals that have the same carrier frequency and measures the strength (received Ec/Nt) of the pilots.  When the mobile station detects a Pilot of sufficient strength that is not associated with the serving cell/sector, it sends a message to the serving … Read more

How Modulation-QPSK in CDMA ?

     In an actual application, the system implements the modulation in this way:  as shown above, I and Q channel sequences in the figure represent two channels of cyclic PN short code sequences.  The cyclic period of each channel of PN short codes is 215. For different sectors, there are different starting locations of I … Read more

Forward Traffic Channel of CDMA

Forward Traffic Channel is used to Transmit Data and Signaling Information. Symbol repetition makes symbol streams at different rates adapted to those at the rate of 19.2k. The original symbol stream at  the rate of 19.2Kbps will not be repeated, 9.6Kbps symbol stream will be repeated once, 4.8Kbps symbol stream will be repeated twice…. Then, … Read more

What is inside SIM Card (Subscriber Identity Module) ?

Subscriber Identity Module (SIM) The SIM as mentioned previously is a “smart card” which plugs into the ME and contains information about the MS subscriber hence the name Subscriber Identity Module. The SIM contains several pieces of information: International Mobile Subscriber Identity (IMSI)This number identifies the MS subscriber. It is only transmitted over the air … Read more

How To Set Pilot Search Window Sizes in CDMA ?

When the handset first powers up, it does an exhaustive search for the best pilot. No windows are used in this process. On the paging channel, the handset learns the window sizes SRCH_WIN_A, N, R and uses them when looking for neighbors both in idle mode and during calls. When a strong neighbor is requested … Read more

Advantages of CDMA Handoff

It is “soft”, meaning that communication is not interrupted by the handoff. This is sometimes called “make before break.” This means fewer dropped calls for users and higher customer satisfaction for operators. The handoff is not abrupt, but rather it is a prolonged call state during which there is communication via two or more base … Read more

Location Area Identity (LAI) and Global Cell Identity (GCI) in CDMA

Location Area Identity (LAI)  PAGING message is broadcast within a local area, the size of which depends on traffic, paging bearer capability, signaling flow , etc. Format:  MCC+MNC+LAC  MCC:  Mobile Country Code, 3 digits. MNC:  Mobile Network Code, 2 digits. LAC:  Location Area Code, a 2-byte-long hexadecimal BCD code. 0000 cannot be used with FFFE. … Read more