Transmitting: The process is similar to that of BS. The frequency offset is pre-corrected. The Ranging and BW Request are generated at the physical layer and a code is selected according to the indication at the MAC layer. After the modulation, they are mapped to competitive slots selected at the MAC layer. Later, they are … Read more
Transmitting: After being processed at the MAC layer, the downlink data is sent to the physical layer inthe format of MAC PDU. The MAC PDU arranges the data block size according to the allocation results of radio resources at the MAC layer. After the data packets are processed through the channel coding, modulation, and IFFT … Read more
In the context of WiMAX (Worldwide Interoperability for Microwave Access), NAP and NSP are important entities that play crucial roles in providing wireless broadband services. What is NAP & NSP in Wimax ? How it Works ? Let’s delve into what NAP and NSP stand for, and how they work together within the WiMAX ecosystem. … Read more
CSN – Core Service Network. Definition It is a combination of a set of network functions and provides IPconnections for the WiMAX subscribers. The CSN consists of the router,AAA agent or server, subscriber database, and Internet gateway equipment. The CSN can a new network entity in a new WiMAX system or can realize the functions … Read more
ASN – Access Service Network. Establish layer 2 connections between the BS and the MS. Transmit AAA messages to the home NSP of the MS. Assist the high level to establish layer 3 connections with the MS and assignthe IP addresses. Perform the radio resource management (RRM). Perform the intra-ASN mobility management and handover. Perform … Read more
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