The requirement that the BCCH TRX must transmit continuously in all the time slots sets strict limitations on how the frequency hopping can be realized in a cell. The current solutions are Baseband Frequency Hopping (BB FH) and Synthesized Frequency Hopping (RF FH). In the baseband frequency hopping the TRXs operates at fixed frequencies. Frequency … Read more
Slow and Fast Frequency Hopping in GSM Frequency hopping can be briefly defined as a sequential change of carrier frequency on the radio link between the mobile and the base station. In GSM, one carrier frequency is divided into eight time slots. Each time slot provides one physical channel, which can be assigned to one … Read more
When mobile has been selected successfully the mobile now will start reselection tasks. Perform Cell reselection measurement first Mobile will continuously make measurements on its neighboring cells (as indicated by the BA list) to initiate cell reselection if necessary. At least 5 measurement sample per neighboring cell is needed. A running average of the received … Read more
MOBILE IDLE When the mobile is idle, it listens to the best cell to camp. Mobile decides to choose the cell by itself without the help of BSC. This is done by comparing signal strength of each BCCH frequency and if found the strongest then it will camp once the C1 > 0 (Cell Selection … Read more
RxLevAccessMin Parameter is decide to allow mobile to access Network.its also used to reduce access on any BTS. RxLevAccessMin = Mobile Sensitivity + Body loss + Multipath loss + Interference Margin Mobile Sensitivity = -104 for GSM900 and -102 for DCS1800 Body loss : = 3 dB recommended by ETSI and 5 dB for GSM … Read more
Once the mobile is switched on and the registered home PLMN was selected (e.x. SMART), it will next search for a BCCH frequency list, stored in its memory or in its SIM card. The list can have up to 32 BCCH frequencies for the mobile to scan. This reduces the time of cell selection, compared … Read more
When the mobile is switched on it will select the registered PLMN in the mobile if there exist one. If there is no registered GSM PLMN or the registered PLMN is not available (no coverage) then the GSM mobile will try to select another GSM PLMN either automatically or manually depending on it mode. AUTOMATIC … Read more
The SIM card contains its internal memory, in which the data, personal and financial information as well as the identity for GSM / CDMA are stored. The SIM card stores network-specific information in order to authenticate the identity of the subscriber in the network. SIMs were first launched in 1992 with the first digital “GSM” … Read more
MOBILE STATIONS ISDN NUMBER (MSISDN) Is the mobile number used in a GSM PLMN (Public Land Mobile Network) MSISDN = Country Code + National Destination Code + Subscriber number e.x. 63 + 0918 + 8889999 Maximum length is 15 digits. INTERNATIONAL MOBILE SUBSCRIBER IDENTITY (IMSI) Is the subscriber number used over radio path for all … Read more
In RF Hopping mode, each route of service information is processed by fixed base band unit and and carrier frequency processing unit, while the working frequency carrier of carrier frequency processing unit is provided by frequency synthesizer. Under the control of the control unit, frequency carrier can be changed according to certain rules. This mode … Read more