SACCH and FACCH difference: the SACCH report base station, said another district to provide better signal quality to the mobile phone, the switch is necessary and within the period of time, due to the SACCH does not have enough bandwidth, so in a short time, replaced by FACCH TCH ; switch FACCH like the one the TCH. hear a voice small interrupt might happen in the switch. TCH Traffic Channel and the random access channel. TCH: call channel carrying voice messages, two-way exchange of voice messages for mobile phones and base stations. RACH Random Access Channel: by phone to send a short burst to the base station, that is, call demand; used by MS to gain attention from the base station. Every channel of the detector of?? cellphone jammer ? ? intelligent system has a piece of antenna with four pieces in total.
The phone does not know the path delay, so the mobile phone short BURST BURST when the phone is moved from time to time, the phone only made a normal downlink RACH. First search for the 124 letter tract, that all of the BCH channel, the decision received by the broadcast channel BCH strength (the BCH carrying the information is from the Mobile recent the BTS; call information); with the network synchronization time and frequency, by the FCH / the SCH adjustment frequency and time. Sub-channel decoding BCH BCCH network to check the legal status of the SIM card is a network allows the SIM card. Handset to the base station transmit channel needs the phone to send a short then access burst (RACH Burst). Detector of? cell phone jammer? intelligent system has the (red) indication light of RF testing.
GPRS is the abbreviation of General Packet Radio Service (General Packet Radio Service), is based on the GSM wireless packet switching technology to provide end-to-end wide-area wireless IP connectivity. GPRS is a packet data transmission technology on the GSM network now opened. Relative to the original GSM dial-up access to the circuit switched data transmission. GPRS is a packet switching technology, ?always on?, ?automatic switching?, the ?high-speed transmission, etc.. GPRS is not a new network, it is as a second-generation mobile communications technology for GSM to third generation mobile communication (3G) transition technology. Receiving antenna of the detector of ?? cell phone jammer ? ? intelligent system is the soft whip omnidirectional antenna.
GPRS is a GSM-based mobile packet data services, user-oriented mobile packet IP or X.25 connections. GPRS in the existing GSM network based on the superimposition of a new network at the same time increase the number of hardware and software upgrades on the network to form a new network logical entity, to provide end-to-end wide-area wireless IP connectivity. GPRS uses packet switching technology, each user can simultaneously occupy more than one radio channel, the same radio channel can be shared by multiple users and resources are effective. The mobile phone uplink channel baseband signal transmitting circuit modulation to transform 880 to 915MHz/1710 to 1785MHz emission from the antenna side out. Installation procedure and method of the detector of?? phone jammer ? ?? intelligent system will be introduced in the following.
The receiving antenna terminal 925 to 960MHz/1805 to 1880MHz base station transmit wireless signals through the receiver demodulation processing circuit, the downstream channel baseband signal; provide a stable and controllable 26.0MHz frequency source for mobile phones. Functions can be divided into four sub-units: antenna unit, receiver unit, the firing unit and the external Crystal cell circuit. By the antenna components, antenna switch, front-end mode fast. The antenna is a wireless signal transceiver device in the mobile communication system, the space of the wireless signal transmitting and receiving rely on the mobile antenna. The transmitter launch of the RF signal to the antenna, through the feeder conveyor and a form of electromagnetic waves radiated by the antenna. Commissioning method of the detector of? cell phone jammers ? intelligent system will be described.
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