無(wú)線網(wǎng)路技術(shù)的應(yīng)用-全文預(yù)覽
【正文】 ctionality (. call chains)n Content Formatsn business card (vCard )n calendar event (vCalendar )n Layered Telemunication Stack2/2/2023 42成大資訊 鄭憲宗Comparison2/2/2023 43成大資訊 鄭憲宗2/2/2023 44成大資訊 鄭憲宗Goals for WTP (WAP )n a mon interface to physical transport mechanismsn provide a port based abstract interface to upper layer protocolsn allow applications designed independent from specific transportsn extensible to a variety of digital wireless works and future transport options2/2/2023 45成大資訊 鄭憲宗Goals for WTP (cont.)n supports connection oriented, transaction, and datagram modesn optimize for narrow to medium bandwidth channelsn to be capable of implementation in a low memory footprint, suitable for standard or low IQ handsets2/2/2023 46成大資訊 鄭憲宗Requirements for WTPn WTP/ C provides a reliable connection oriented service to the upper layern WTP/ T provides a reliable transaction oriented service suitable for web browsingn WTP/ D provides a datagram servicen lightweight : implementable in = 10Kb (low memory / putational needs)2/2/2023 47成大資訊 鄭憲宗WTP/D features (WDP in WAP v )n WTP/ D (Datagram) provides a connection less, unreliable datagram servicen WTP/ D is replaced by UDP when used over an IP work layer.n uses the Service Primitiven T UnitData. req .ind2/2/2023 48成大資訊 鄭憲宗WAP v Wireless Bearers:SMS USSD CSD IS 136 CDMA IDEN CDPD PDC P GPRSWireless Application Environment (WAE )Wireless Session Protocol (WSP)Wireless Transaction Protocol (WTP)Wireless Transport Layer Security (WTLS)Datagrams (UDP/IP) Datagrams (WDP)Other Services andApplications2/2/2023 49成大資訊 鄭憲宗WTP/T features (WTP in WAP v ) n WTP/ T (Transaction) provides reliable data transfer based on request/ reply paradigmn no explicit connection setup or tear downn data carried in first packet of protocol exchangen seeks to reduce 3 way handshake on initial request2/2/2023 50成大資訊 鄭憲宗WTP/T features (cont.) n supportsn retransmission of lost packetsn selective retransmissionn segmentation / re assemblyn port number addressing (specific to WTP/ T)n flow controln message oriented (not stream)n supports an Abort function for outstanding requests2/2/2023 51成大資訊 鄭憲宗Wireless Session Protocol n WSP/ B provides upper layers with session services and managementn WSP/ B Provides semantics and mechanisms based on HTTP n WSP provides means to : n establish a reliable session from client to servern agree on mon level of protocol functionality by capability negotiationn pact encodingn suspend and resume2/2/2023 52成大資訊 鄭憲宗WSP featuresn HTTP functionalityn Exchange of client and server session headersn Interrupt mechanism for transactions in processn Content Push from server to clientn Negotiation for multiple, simultaneous asynchronous transactions2/2/2023 53成大資訊 鄭憲
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