Nokia has announced another huge shake-up of the company, with the loss of 10,000 jobs by the end of next year. While planning to significantly reduce its operating expenses, Nokia also announce an increased emphasis on location-based services. The planned job losses are expected to come from the closure of its facilities in Ulm, Germany … Read more
Adaptive Multi-Rate (AMR) codec consists of a family of codecs (source andchannel codecs with different trade-off bit-rates) operating in the GSM FRand HR channels modes The AMR system exploits the channel performance and robustness added bythe coding rates by adapting the speech and channel coding rates accordingto the quality of the radio channel AMR adapts … Read more
Dedicated Control Channel (DCCH) in GSM SDCCH (Stand-alone Dedicated Control Channel) Uplink and Downlink. Used for call setup, authentication, ciphering location update and SMS. SACCH (Slow Associated Control Channel) Downlink and Uplink. Used to transfer signal while MS have ongoing conversation on traffic or while SDCCH is being used. On the forward link, the SACCH … Read more
BCCH(Broadcast Control Channels) Downlink Only. Broadcast information of the serving cell (System Information). Transmitted on timeslot zero of BCCH carrier. Read only by idle mobile at least once every 30 secs. SCH (Synchronization Channels) Downlink Only Carries information for frame synchronization. Contains frame number and BSIC (Base Station Identity Code). FCCH (Frequency Correction Channels) Downlink … Read more
Exchange where calls are established, maintained and released Database for all subscribers and their associated features. Communicates with the BSCs on the A interface and with PSTN on fixed line. MSC is weighted on the number of subscribers it can support. For example, an MSC of 1 lakh subscribers means one MSC is enough till … Read more
Advantages of Intelligent Network (IN) Concept of Intelligent Network: The introduction of new services and access to the GSM service are based on the concept of Intelligent Network (IN). This is because of the independence between: Conventional call processing handled by the exchange, Mobile radio functions handled by a dedicated server. Dialog between these two … Read more
Channel Bandwidth 5 MHz Duplex Mode FDD and TDD Downlink RF Channel Structure Direct Spread (DS) Chip Rate 3.84 Mcps Frame Length 10 ms Spreading Modulation Balanced QPSK (downlink) Dual-channel QPSK (uplink) Complex spreading circuit Coherent detection • User dedicated time multiplexed pilot (downlink and uplink) • common pilot in downlink Channel Multiplexing in Downlink … Read more
Support two basic modes: FDD and TDD modes High chip rate (3.84 Mcps) and data rates (up to 2 Mbps) Employs coherent detection on uplink and downlink based on the use of pilot symbols Inter-cell asynchronous operation Fast adaptive power control in the downlink based on SIR Provision of multirate services Packet data Seamless inter-frequency … Read more
E-UTRAN (Evolved Universal Terrestrial Radio Access Network) E-UTRAN, or Evolved Universal Terrestrial Radio Access Network, is the radio access network component of the LTE (Long-Term Evolution) architecture. It plays a central role in providing high-speed wireless communication for mobile devices. Here’s a brief summary of E-UTRAN: Evolved NodeB (eNB): The fundamental building block of E-UTRAN … Read more
The initial range is the process of estimating the distance or propagation time between a transmitter and a receiver. Area information can be used to assist in setting operating parameters for the transmitter and receiver. Since each MS has a unique distance from the base station, it is critical in the uplink to synchronize the … Read more