A data-modulation scheme defines how the data bits are mixed with the carrier signal, which is always a sine wave. There are three basic ways to modulate a carrier signal in a digital sense: amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK). In ASK the amplitude of the carrier signal … Read more
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
Transmit Diversity MISO = Multiple Input Single Output Principle More complex than SISO. 2 or more transmitters and one receiver. MISO is more commonly referred to as transmit diversity. The same data is sent on both transmitting antennas but coded in such a way that the receiver can identify each transmitter. Benefits Transmit diversity increases … Read more
Paging Control Channel(PCCH) A downlink channel that transfers paging information and system information change notifications. This channel isused for paging when the network does not know the location cell of the UE Broadcast Control Channel (BCCH) Provides system information to all mobile terminals connected to the eNodeB. A downlink channel for broadcasting system control information … 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
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
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
OFDMA is essentially a hybrid of FDMA and TDMA: Users are dynamically assigned subcarriers (FDMA) in different time slots (TDMA) . The advantages of OFDMA start with the advantages of single-user OFDM in terms of robust multipath suppression and frequency diversity. In addition, OFDMA is a flexible multiple-access technique that can accommodate many users with … Read more
Fixed WiMAX offers cost effective point to point and point to multipoint solutions. What makes WiMAX so exciting is the broad range of applications it makes possible but not limited to broadband internet access, T1/E1 substitute for businesses, voice over Internet protocol (VoIP) as telephone company substitute, Internet Protocol Television (IPTV) as cable TV substitute, … Read more