GSM

Time Division Multiple Access (TDMA) is advantageous due to its efficient use of bandwidth by dividing it into time slots, ensuring fairness among users, predictable access, low latency, ease of implementation, scalability, collision avoidance, support for Quality of Service (QoS), energy efficiency, and multiplexing capabilities, making it suitable for a wide range of communication systems. … Read more

How do you calculate total radiated power antenna? Calculating the total radiated power (TRP) of an antenna involves determining the power radiated in all directions by the antenna. The TRP is a measure of how effectively an antenna transmits energy into free space. Here’s a detailed explanation of how to calculate the TRP of an … Read more

What is Advanced Audio Coding used for? Understanding Advanced Audio Coding (AAC) Advanced Audio Coding (AAC) is a digital audio file format commonly used for storing and compressing audio data. It has gained widespread popularity for its efficient compression, which allows for better audio quality and smaller file sizes compared to its predecessor, MP3. AAC … Read more

What is the difference between authentication and authorization in Cisco AAA? Authentication and authorization are two essential components of the Cisco AAA (Authentication, Authorization, and Accounting) security framework. While both processes contribute to network security, they serve distinct purposes in granting access and controlling permissions. Authentication is the process of verifying the identity of a user. … Read more

Interference is dependent on time, frequency and mobile location. Without frequency hopping, some cell planning margins must be incorporated so that sufficient service quality can still be provided in an interfered situation. By changing frequency on every TDMA frame, a mobile only experiences interference on a particular frequency once in a number of hops. Similarly, … Read more

Broadcast Channels (BCH) Frequency correction channel (FCCH) the “lighthouse” of a BTS Synchronization channel (SCH) PLMN/base identifier of a BTS plus synchronization information (frame number)  Broadcast control channel (BCCH) to transmit system information 1-4, 7-8 (differs in GSM 900, GSM 1800, and PCS 1900) CBCH and CCCH CBCH (Cell Broadcast Channel) transmits cell broadcast messages … Read more

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

RACH(Random Access Channel) Uplink only. Used by the MS when making its first access to the Network. The reason for access could be initiation of a call or a page response. AGCH (Access Grant Channel) Downlink only. Used for acknowledgement of the access attempt sent on RACH. Used by the network to assign a signaling … 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