Understanding Discord NSFW Servers A Guide for Responsible Users.pdf
Cdma presentation
1. ZTE Basic knowledge of CDMA MSC Based WLL (BSNL) Compiled by: M.Pandian, Divisional Engineer CDOT Installation, Salem-1 E-Mail: cdotpandian@rediffmail.com
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3. Advantages of CDMA Frequency reuse facto is 1; network design and expanding become much easier AMPS , D-AMPS , N-AMPS CDMA 30 30 10 kHz 200 kHz 1250 kHz 1 3 1 Users 8 Users 20 Users 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 3 4 4 3 2 5 6 1 7 Typical Frequency Reuse N=7 Typical Frequency Reuse N=4 Typical Frequency Reuse N=1 Vulnerability: C/I 17 dB Vulnerability: C/I 12-14 dB Vulnerability: E b /N o 6--7 dB GSM
4. Advantages of CDMA large coverage almost 2 times than GSM, save money for operator Example:cover 1000 km 2 ： GSM need 200 BTS ， CDMA only need 50 BTS Attention: exact result need “ Link Budget ”
5. Advantages of CDMA High spectrum capacity: 8--10 times than AMPS, 4—6 times than GSM FDMA---Different user use different frequency TACS 、 AMPS TDMA---Different user use different time slot of one frequency GSM 、 DAMPS CDMA---Different user use same frequency at the same time,but with different spreading code Frequency Time Power Frequency Time Power Frequency Time Power FDMA TDMA CDMA
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8. Advantages of CDMA Good voice quality, use 8k,13K(QCELP,EVRC)voice coding—the best coding method in the world. Voice quality (MOS) 64k PCM 13k GSM 8k CDMA 13k CDMA 8kEVRC CDMA
9. Advantages of CDMA Perfect Power Control and voice activation make the MS Power low, healthy for humanbody—green mobile phone. Mean Power Max Power GSM: 125mW 2W CDMA: 2mW 200mW
17. Architecture of CDMA system Um E Abis A Q C B N N MS BT S B S C PSTN M S C M S C/SSP VLR HLR AUC MC D MC M MSS BSS Ai
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27. Operation and Maintenance Center (OMC) OMC provides operation and maintenance services to the network operator, manages the registered subscriber information and conducts network planning to enhance the overall working efficiency and service quality of the system. Based on the main maintenance functions, there are two types of operation and maintenance centers: OMC-S and OMC-R . The OMC-S is mainly responsible for maintenance of MSS while the OMC-R is mainly for BSS. We also call OMC as background . Architecture of CDMA system
44. CDMA MS Call Processing Power-Up Initialization Idle System Access Traffic Mobile station has fully acquired system timing Mobile station receives a Paging Channel message requiring ACK or response, originates a call, or performs registration Mobile station is directed to a Traffic Channel Mobile station ends use of the Traffic Channel Mobile station receives an ACK to an Access Channel transmission other than an Origination Message or a Page Response Message Mobile station is in idle handoff with NGHBR_CONFG equal to ‘011’ or is unable to receive Paging Channel Message
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Hinweis der Redaktion
A CDMA system includes four independent subsystems: mobile station (MS), base station subsystem (BSS) and mobile switching subsystem (MSS). OMM
BSS is a general term for wireless equipment and wireless channels control equipment serving one or several cells. Usually, BSS consists of one or more Base Station Controllers (BSC) and Base Transceiver Stations (BTS).
AS the central part of cdma system, MSC serves to control the mobile stations that are within its controlling sphere, and to perform the channel switching. It functions as the interface between the mobile system and the other public telecommunication means. MSC provides the network interfaces, the charging function and the function of processing the common channel signaling. It can process the No. 7 signaling between BSS and MSC, and realizes the auxiliary radio resource management and mobile management. In addition, for the sake of establishing the calling route to the mobile station, each MSC can function as a Gateway MSC (GMSC). If a network transfers a call to PLMN, but if it cannot query HLR, then the call will route to a MSC. This MSC will query related HLR, and rout the call to the MSC where the called subscriber is located. This kind of MSC is called a gateway MSC (GMSC). Which MSCs are to be chosen as GMSC depends on the network service carrier.
The VLR is a location register used by MSC for information index. It saves and updates data of mobile subscribers who roam to this VLR service area. VLR can be built together with the MSC or set separately, in the former case, interface B turns to be an internal interface.
The HLR is a location register used for registering identity of subscribers, including subscriber information (ESN, MDN, IMSI, MIN), service information, current location and valid term, etc. HLR can be built together with the MSC or set separately. In case of the former, interface C turns to be an internal interface.
Authentication center is a functional entity for the management of authentication information related to the mobile stations. It functions to authenticate mobile subscribers, save authentication parameters of mobile subscribers and generate and send corresponding authentication parameters in response to the request from MSC/VLR. AUC can be built together with HLR or set separately. In case of the former, interface H turns to be an internal interface.
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