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Access Network Planning and Technologies. Part1 structure of Access Network. Conception of Access Network Access Network(exchange) is the subscriber part of the telecommunications network. The basic idea of telecommunication is the exchange of information. Voice text data image video.
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Access Network Planning and Technologies Part1 structure of Access Network
Conception of Access Network • Access Network(exchange) is the subscriber part of the telecommunications network. The basic idea of telecommunication is the exchange of information. • Voice • text • data • image • video
If you are a telecommunications service provider and you have set up you first switch. You just need to link the customer premises equipment(CPE) to you witch with a pair of copper conductors . Simple interconnection of subscribers to exchange
Structure of the Access Network DP1 2000 pairs 400 pairs EXCHANGE SCP PCP DP2 DP3 To other SCPs
Limitation of the copper network • limited bandwidth and there are problems in overcoming. • Inflexibility: both in time and types of service provisioning. • Reliability is limited. • Installation time is long. • Possible cable damages and maintenance costs were high. • Difficult to manage • Loop length limitations(~ 5km) • Has problem of security • Uneconomical in remote • Prone to electromagnetic interference
New technologies in the copper Access Network Name Meaning Data Connection Distance Application Rate type to exchange DSL Digital 160kb/s Symmetrical ~5 km ISDN series, voice, Subscriber data communication line HDSL High Data 2Mb/s Symmetrical 4-5km No POTS, E1, LAN/ Rate Digital WAN, Internet Service Subscriber line access SDSL Single Line 2Mb/s Symmetrical 3-4km Same as HDSL+POTS Digital Sub- Work at home, scriber line internet access ADSL Asymmetric Downstream Asymmetrical 3-6km Internet access, video on d- Digital Sub- 2-8Mb/s, Up- emand, remote LAN access scriber line stream 128kb/s-768kb/s interactive multimedia VDSL Very High Downstream 13- Asymmetrical 0.3-1.5km Same as ADSL Data Rate 52Mb/s, HDTV Digital Sub- Upstream 1.5- scriber Line 2.3Mb/s
Fiber based new technologies in the Access Network • Methods of deployment of fiber • Fiber to the Curb(FTTC) • Fiber to the Building(FTTB) • Fiber to the home/office(FTTH/FTTO) • Fiber in the loop architectures • Point-to-point • Point-to-multipoint/star • Tree • Ring
Technological options • 1. PDH(plesiochronous digital hierarchy) • fiber optic cabinet • PON(passive optical network) • AON(active optical network) 2. SDH(synchronous digital hierarchy)
Basic PON system components • OLT(optical line terminal) • Splitter • ONU(optical network unit)
Typical implementation of PONs ONU Management Up to 4 PONs ONU 1 Switch ONU 2 OLT 3 Capacity: 4B-120B 4 Splitting up to 32 Capacity: OLT 1920B, PON 480B B: 64Kb bearer channel
Advantages of PON/AON • Sharing of fiber and equipment as in case of PONs • Increase in range at the cost of an additional active component(splitter) • High flexibility in structures • Higher capacity • Management
Future of PON systems ATM-PON(APON): One fiber is passively split up to 64 times. Serve more customers. Can savings 20%-40% over circuit based access systems.
Future of PON systems ATM-PON(APON): One fiber is passively split up to 64 times. Serve more customers. Can savings 20%-40% over circuit based access systems.