電信行業(yè)--3g、b3g、all-ipv6在多媒體傳輸上之應(yīng)用-文庫吧在線文庫
【正文】 ting ? GSN : GPRS Support Node ? SGSN : Serving GSN ? GGSN : Gateway GSN ? BG : Border Gateway ? GR/HLR : GPRS Register/ Home Location Register Packet Data Routing Mobility Management ? Two encapsulation schemes: – Between GSNs – Between MS and SGSN ? Before MS sends data, MS has to attach to GPRS using an attachment procedure ? When moving to another SGSN(location update), GGSN and GR/HLR are informed about the new routing context Protocol Architecture Protocol Architecture ? Physical layer: – RFL – PLL ? Data Link layer: – MAC – RLC – Logical Link Control(LLC) Layer Protocol Architecture Protocol Architecture ? GPRS supports interworking of MSs with , IPbased works by encapsulation and decapsulation ? Between SGSN and MS, further encapsulation is performed by SNDCP ? The MAC is derived from a slotted reservation ALOHA protocol, and operate between MS and BTS Protocol Architecture Protocol Architecture Some optimizations are still ongoing ? Channel allocation ? Backoff strategy ? QoS handling ? 靜夜四無鄰，荒居舊業(yè)貧。 GSM網(wǎng)路 ? 基地臺 (Base Station) –負(fù)責(zé)無線傳輸，每個基地臺所涵蓋的範(fàn)圍稱為細(xì)胞（ Cell），整個系統(tǒng)由多個基地臺所構(gòu)成，因此也就稱為蜂巢式行動電話了 ? 行動交換機(jī) (
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