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【正文】 d generation system mostly prise the ( A ).A. RAN and CN。 D. TDM and FDM.29．A GSM cell can have a radius of between( B ), depending on the environment.A. 100 m and 5kmB. 100m and 35km。 C. MS and CN。 D. slow.23．( D ) is the procedure for changing the assignment of a mobile unit from one BS to another as the mobile unit moves from one cell to another. A. Transmission。 B. MS, MSC and BS。 C. RAKE。15．Cellular system use the two kinds of power control, they are ( A ).A. Openloop power control and closedloop power control。 FDMA and CDMA。 B. BS, NS and MS。 C. 8。5．The boundaries at Um, Abis, and A refer to interfaces between functional elements that are standardized in the ( B ) documents.A. AMPS。 C. guided and unguided。（2）Reflection；（3）Diffraction.16．In time, as more customers use the the system, traffic may build up so that there are not enough frequency bands assigned to a cell to handle its calls. A number of approaches have been used to cope with this situation, including the following。名詞解釋1．Explain the difference between hard and soft handoff.Answers：The hard handoff is that when the signal strength of a neighboring cell exceeds that of the current cell, plus a threshold, the mobile station is instructed to switch to a new frequency band that is within the allocation of the new cell.The soft handoff is that a mobile station is temporarily connected to more than one base station simultaneously. A mobile unit may start out assigned to a single cell. If the unit enters a region in which the transmissions from two base stations are parable, the mobile unit enters the soft handoff state until which it is connected to the two base stations.2．What are the cores techniques of WCDMA?Answers: The WCDMA key techniques mostly consist of the power control technique, PN code technique, RSKE, Soft Handoff, and Speech coding.3．What is attenuation?4．What two functions are performed by an antenna?5．What are the advantages of using CDMA for a cellular network?Answers: (1)Frequency diversity。Answers: (1)Adding new channels；(2)Frequency borrowing；(3)Cell splitting；(4)Cell sectoring；(5)Microcells。 D. wired and wireless.3．Fading effects in a mobile environment can be classified as either ( A ).A. fast or slow。 B. GSM。 D. 10.8．The GSM spectral allocation is 25MHz for base transmission ( D ) and 25MHz for mobile transmission( 890—915MHz).A. 1805—1880MHz。C．CDMA2000,WCDMA and CDMA。 D. TDM and FDM.13．For direct sequence spread spectrum (DSSS), each bit in the original signal is represented by multiple bits in the transmitted signal, using a ( B ). A. code 。 B. MS and BS。 D. Power control.18． Which of the following is core technique of the TDSCDMA? ( B ) A. Transfers。 C. MS, RAN and CN。 B. change。 D. RAN and BS.26. The cellular mobile munication system consist of three parts, they are ( B ).A. TDMA, FDMA and CDMA。 C. 100m and 50km。 B. MS and BS。 D. RAN and BS.33. The same frequency assignments cannot be made in adjacent cell because of ( B ).A. multipleaccess interference。 B. secondly。 C. CDMA2000,WCDMA and CDMA。 D. Handoff.24．Fast fading is due to reflections of local objects and the ( D ) of the terminal relative to those objects. A
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