Sistem Broadband Pertemuan 13 Matakuliah: H0122 / Dasar Telekomunikasi Tahun: 2008

Bina Nusantara 2 Mahasiswa dapat menyebutkan sistem akses broadband yang telah digunakan. Learning Outcomes

Bina Nusantara 3 X-DSL Modem Kabel Outline Materi

Bina Nusantara 4 The need broadband system is due to the user demand for speed on the order of Mbps for internet access and other applications. The bandwidth of the basic POTS analog is limited. High Speed means Megabits at least in one direction, always on for continuous connection to the outside world and bidirectional. High speed from the home as well as to the home. Broadband

Bina Nusantara 5 Access Choices Many different approaches – Twisted pair (xDSL) – Hybrid fiber-coax cable (cable modem) – Fixed wireless – Satellite (two-way) – Fiber to the home or curb (Gigabit Ethernet) – Power line – Digital terrestrial

Bina Nusantara 6 Access Choices Determining Factors: Population density Existing infrastructure (e.g., twisted pair, cable, fiber) Government policies Competitive and regulatory dynamics Technology evolution Farm Homes MDU GigE Fiber Cable modem Twisted pair DSL Satellite High-rise multi- dwelling units Individual single units Isolated single units Communication Network

Bina Nusantara 7 Digital Subscriber Line Digital Subscriber Line (DSL) technology is one of the most supporting high-speed digital communication over the existing local loops. DSL provides high speed access over local loops. The various types of DSL are called xDSL family = {A,S,H,V}DSL Twisted Pair cables used for local loops has a bandwidth of 1.1MHz Telephone companies limit the bandwidth to 4KHz using filters (sufficient for voice communication), to allow multiplexing of large number of voice channels

Bina Nusantara 8 Types of xDSL SDSL: Symmetrical DSL, the bandwidth partitioning is symmetrical, suitable for businesses ADSL: Asymmetric Digital Subscriber Line HDSL: High-bit-rate DSL (repeaterless E1) RADSL: Rate Adaptive DSL for noisy lines VDSL: Very-high-speed DSL upstream Mbps, coaxial, fiber-optic, or TP for higher rates over short distances ( m) G.Lite: Slower version of ADSL eliminating need for POTS Splitter (filter) at customer. Provides up to 1.5 Mbps down, 128 Kbps up

Bina Nusantara 9 Asymmetric – Asymmetry in upstream and downstream connection, higher bandwidth downstream (to subscriber), lower bandwidth upstream (to Internet) Frequency division multiplexing – Lowest 25kHz for voice (POTS) – Use echo cancellation or FDM to give two bands – Use FDM within bands The existing local loops can handle bandwidths up to 1.1 MHz. Range 5.5km ADSL is a link between subscriber and network and uses currently installed twisted pair cable ADSL

Bina Nusantara 10 ADSL is an adaptive technology. The system uses a data rate based on the condition of the local loop line. Factors like the distance between the residence and switching office, line quality, and signaling used affect the data rate ADSL tests the condition and the bandwidth availability before deciding on a data rate ADSL is an asymmetric communication technology designed for residential users; it is not suitable for businesses. ADSL

Bina Nusantara 11 Channel Configuration

Bina Nusantara 12 System Configuration

Bina Nusantara 13 Cable TV Network The cable TV network is a video service provider, it can be used to provide high-speed access to the Internet. Communication in the traditional cable TV network is unidirectional. Communication in an HFC cable TV network can be bidirectional. Downstream data are modulated using the 64-QAM modulation technique. The theoretical downstream data rate is 30 Mbps. Upstream data are modulated using the QPSK modulation technique. The theoretical upstream data rate is 12 Mbps.

Bina Nusantara 14 Hybrid fiber-coaxial (HFC)

Bina Nusantara 15 Cable Modem Configuration

Bina Nusantara 16 Downstream – Cable scheduler delivers data in small packets – If more than one subscriber active, each gets fraction of downstream capacity (may get 500kbps to 1.5Mbps) – Also used to allocate upstream time slots to subscribers Upstream – User requests timeslots on shared upstream channel (dedicated slots for this). – Headend scheduler sends back assignment of future tme slots to subscriber. Cable Modem Operations

Bina Nusantara 17 Telah dipelajari XDSL. Telah dipelajari Modem Kabel. Summary