GSM frequency bands

About: GSM frequency bands is a research topic. Over the lifetime, 559 publications have been published within this topic receiving 5067 citations.

Method for calibrating transmission gsm frequency band power of mobile terminal

Abstract: Disclosed is a method for calibrating the transmission GSM frequency band power of a mobile terminal, including: a calibration system setting a reference channel and reference radio frequency signal line loss of a corresponding working frequency band, the calibration system setting a radio frequency parameter of a mobile terminal, the mobile terminal successively outputting a series of signals with different powers, and a base station emulator of the calibration system reading and storing the corresponding parameters of various power signals; setting a radio frequency signal line loss corresponding to the next channel of the corresponding working frequency band; and the calibration system setting the radio frequency parameter of the mobile terminal, the mobile terminal successively outputting a series of signals with different powers, and the base station emulator reading and storing the corresponding parameters of various power signals. The present invention can set different target powers for different channels. By way of setting corresponding radio frequency signal line losses, the calibration accuracy is improved, which is convenient for debugging mobile phone antennas, and a significant progress over the prior art.

Method and device for session interaction in mode switching

Abstract: Disclosed are a method and device for session interaction in mode switching. The method comprises the following steps: when switching from a Long Term Evolution (LTE) mode to a Time Division (TD) mode or a Global System for Mobile communication (GSM) mode, the Evolved Session Management (ESM) in the LTE mode transmits global data to the Session Management (SM) in the TD mode or the GSM mode, thereby reestablishing the bearer of the control plane, and the global data includes at least one of the followings: flow control parameters, bearer information, packet filtering parameters; the ESM according to the transmission information of the data plane in the LTE mode informs the TD mode or the GSM mode of restarting the packet transmission of the data plane. By the present invention, the problem that in correlation technique there is no specific implementation of mode switching when GSM/TD/LTE networks are converged is solved, thereby improving the processing capability of the system.

An interlaboratory comparison programme on radio frequency electromagnetic field measurements: the second round of the scheme

Abstract: The second round of an interlaboratory comparison scheme on radio frequency electromagnetic field measurements has been conducted in order to evaluate the overall performance of laboratories that perform measurements in the vicinity of mobile phone base stations and broadcast antenna facilities. The participants recorded the electric field strength produced by two high frequency signal generators inside an anechoic chamber in three measurement scenarios with the antennas transmitting each time different signals at the FM, VHF, UHF and GSM frequency bands. In each measurement scenario, the participants also used their measurements in order to calculate the relative exposure ratios. The results were evaluated in each test level calculating performance statistics (z-scores and En numbers). Subsequently, possible sources of errors for each participating laboratory were discussed, and the overall evaluation of their performances was determined by using an aggregated performance statistic. A comparison between the two rounds proves the necessity of the scheme.

Evaluation of a Near Field Scanner For Active Measurements of Mobile Phones

Abstract: The radio performance measurements of terminal antennas require expensive investments and they are often performed in anechoic chambers. Now a days measurement techniques using wheeler cap, reverberation chamber, etc have become popular. But these methods are used for measurements either during the design or production or in-network testing phases but not for all. Hence EMSCAN, a Canadian company, has come up with a device called Lab express near field scanner to counter this problem. In this thesis an attempt is made to study the EMSCAN near field scanner by looking into architecture and design aspects of this device. Moreover, the capability of the device to measure the radio performance of the terminal antennas in terms of radiation pattern and total radiated power (TRP) is also studied and anlaysed.The analysis of the TRP and radiation pattern measurements of the terminal antennas is done by comparing the EMSCAN measurement results of 10 commercially available mobile phones with that of CTIA approved Satimo SG24 chamber. The TRP and radiation pattern measurements are done for GSM 900 MHz and DCS 1800 MHZ low bands i.e.975 and 512 respectively. Furthermore, the dependency of the measured TRP on the positioning of the mobile phone on EMSCAN is tested by measuring the TRP and the radiated power of a single mobile phone. The measurement results after comparison suggest that there is a correlation of around 79% at 1800 MHz and 49% at GSM 900 MHz among the two methods. This leads to the conclusion that EMSCAN scanner cannot replace the anechoic chambers for estimating the radio performance of terminal antennas. The results obtained by measuring the mobile phone in 8 different positions suggest that there is no significant difference in the TRP measured. There is a difference of 1.25dB was observed between the maximum and minimum TRP measured in two different positions on the near field scanner. The results obtained by both the methods are verified by computing the TRP and radiation pattern in Matlab.The Matlab results agrees more with the EMSCAN results than Satimo SG 24 chamber results.

Multi-band Internal antenna for DVB-H and GSM services

Abstract: We propose a multi-band internal antenna for the DVB-H and the GSM services. The proposed antenna consists of a tunable PIFA for the DVB-H service and a dual band folded monopole for the GSM 900 and the DCS 1800. The resonant frequencies of the designed antenna are independently adjusted. It can be used for a complex mobile set for a broadcasting service.