FTTH Fiber To The Home Alpesh Desai SDE
FTTH Fiber To The Home Alpesh Desai SDE BB, RTTC Ahmedabad
FTTH Ø Today, majority of broadband connectivity is offered through Digital Subscriber Line (DSL), Cable Modem and to the limited extent with Wireless technology. Ø FTTH which provides Higher Bandwidth is future proof solution for providing add-on services such as Video on demand, Online Gaming, HDTV etc
Fiber To The Curb
Fiber To The Building
Fiber To The Home
What is PON? PON - Passive Optical Network Ø It is cost effective optical fiber based access system Ø It provides triple play services (voice, video & data) to customers
Why PON required? • Due to bandwidth limitation of copper cable, Optical signal is to be distributed on Fiber • PON provides High bandwidth with reduced COST & complexity • No conversion required for O-E-O • PON uses optical fiber and optical power splitters
Why PON required? Ø High bandwidth requirement for Voice, Data & Video at Distribution / Ø User end Bandwidth required for Ø Hi definition TV, Ø High speed internet access, Ø High speed data transfer, Ø Video on demand, Ø IPTV, Online gaming, Distance learning, etc.
PON FIBRE P O N Central Office (CO) Customer Premise Equipment (CPE)
Types of PON configurations v Point-to-point Ethernet v Point-to-multipoint switched Ethernet v Passive Optical Splitter
PON configurations Point To Point CO P 2 M Switched Ethernet CO CO Passive Optical Splitter
Cascaded Splitter:
Passive Splitter (1: 16)
FTTH Architecture Voice NMS Data ONU Other Networks Video TDM ONU PABX 1: 32(64) Optical Splitter O L T PO N TDMA Data Central Office ONU 0 -20 Km physical reach (60 Km logical reach supported by protocol) Video/Audio over IP services CATV overlay services IP N/Ws
Elements of PON The basic elements in any PON system are: OLT : A Central Office (CO) equipment providing PON with the various network interfaces ONU/ONT : An External Plant / Customer Premises equipment providing user interface for many/single customer PON : Passive optical splitters/combiners providing connectivity between OLT & multiple ONU/ONTs through optical fibers NMS : Management of the complete PON system
1. OLT: Ø Ø Ø OLT resides in the Central Office (CO) OLT provides switching functionality between the core network (various network interfaces) and PON OLT is typically connected to: * IP network and * Backbone of the network operator
2. ONU/ONT v ONU/ONT provides access to users i. e. an External Plant / Customer Premises equipment v providing user interface for many/single customer v installed within user premises for network termination is termed as ONT v Access node installed at other locations i. e. cabinet /building, are known as ONU
ONT (CPE)
3. PON: Ø Distributed or single staged passive optical splitters /combiners Ø provides connectivity between OLT & multiple ONU/ONTs Ø Connectivity through one or two optical fibers Ø Optical splitters are capable up to 1: 64 optical split, on end to end basis. Ø These are available in various options like 1: 4, 1: 8, 1: 16, 1: 32 and 1: 64
Cascaded Splitter:
4. NMS: Management of complete PON system from OLT • One OLT serves multiple ONU/ONTs through PON • TDM/TDMA protocol Single Fiber/ Dual Fiber to be used for upstream & downstream • Protection for taking care of fiber cuts, card failure etc. • Maximum Split Ratio of 1: 64 • Typical distance between OLT & ONT can be greater than 15 Km (with unequal splitting - up-to 35 Km) • Downstream transmission I. e. from OLT to ONU/ONT is usually TDM • Access from ONU/ONT to OLT is TDMA
Bandwidths & Services Upstream Downstream 1310 nm 1490 nm Voice and Data 1550 nm POTS Video ONT Data ONT Video Power & Battery
Downstream Traffic in EPON 802. 3 x frame FCS 4 Payload Header 2 // 1 1 // ONU 1 3 2 1 OLT 3 // // 3 2 1 4 4 // // // 4 3 2 1 2 4 3 4 2 Maximum 64 ONUs can be configured ONU 2 1 Every ONU receives the original Frame which was sent from OLT 3 2 // 1 // ONU 3 ONU filters only the traffic meant for that site with the help of an ID Downstream traffic is normally encrypted to avoid security breach 3 ONU 4 // 4 3 2 1 4
Upstream Traffic in EPON (TDMA) 802. 3 x frame Header Payload 1 FCS OLT 1 // 1 2 // ONU 1 ONU 2 // // 1 2 3 // 4 // // ONUs share the bandwidth in TDMA Fashion when sending the traffic to OLT (upstream) 3 Sufficient gap ( laser off) is maintained between frames from ONUs to avoid overlapping Upstream traffic from one ONU cannot be seen by other ONUs by the Physics of Splitter/coupler 2 2 3 4 // 3 // ONU 3 ONU 4 // 4 4
Multi- Point-Control-Protocol (MPCP) • The OLT needs an arbitration scheme (MPCP) so it can schedule and control the traffic coming from the ONUs • OLT sends a GATE (grant) message in the downstream channel to the ONU, in which transmission information (start time, transmission length) are included.
Multi- Point-Control-Protocol (MPCP) • ONU sends a REPORT (request) message in the upstream to the OLT at the end of its transmission to notify the OLT of its buffering queue status. • OLT needs to take distance(between OLTs and ONUs), traffic priority and Qo. S problems into account while granting access to ONU
Types of PONs • EPON (Ethernet Passive Optical Networking) (Japan) • GPON (Gigabit Passive Optical Networking)
GPON vs EPON
GPON System Interfaces
GPON Application
Video Services n n Transports 89 Channel PAL CATV Analog Video Channels over dedicated 1550 nm wavelength Bandwidth of 45 – 862 MHz
Application Areas – Wireless Backhaul Applicable ONT Types: B-ONU – Cat I
Protection in GPON Full-Tree Protection Some ONTs may be not protected Double fiber route to a protected ONT
GPON Architecture Gig. E Switch Ethernet Transport ONT ADM ONT MADM ONT Splitter 1: N SDH Transport OLT ONT PON Access Network Fiber Distribution Central Office
ONT Types & Applications Internet Browsing VPLS, VPLAN Basic Telephony (SIP) E 1 PBX Cable TV STM 1 CPE replacement IP TV Basic Telephony (SIP) Cable TV, IP TV Applications Internet Access VPLS, VPLAN VPLS/VPLAN Internet Access Basic Telephony (SIP) E 1 Cable TV, IP TV IP DSLAM interface Cable TV, IP TV
FTTH in Gujarat • Ahmedabad • Gandhinagar • Mehsana • Vadodara • Surat • Anand • Bharuch • Dahej • OLT -61 AM • OLT- 88 GUJ
Thanks Open for DISCUSSION
- Slides: 38