Access Network Technologies

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Access Network Technologies by Mind Map: Access Network Technologies


1.1. cable television networks

1.2. metropolitan networks


2.1. WiMAX

2.2. LTE

3. Performance

3.1. High-speed

3.2. High-sensitivity

4. Pseudorandom binary sequence (PRBS)

5. provides network connectivity over wireless media

6. BER Testing

6.1. Quasi-random signal source (QRSS):


7.1. XG-PON

7.1.1. G.987.1

7.1.2. 10Gbps downstream & 2.48Gbps for upstream

7.1.3. Improvement Security Mechanism Power Saving Option Power Shedding Enabling Mobile Backhauling ODN enhancement performance monitoring

7.1.4. Transmission Capabilities TDMA Split ratio 1:256 20km distance Optical source: 1310nm/1490nm

8. FTTx

8.1. PON

8.1.1. APON Built on ATM

8.1.2. BPON Added Bandwidth Distribution and Protection

8.1.3. EPON Uses Ethernet Packet

8.1.4. GPON High Speed and Power Saving

9. DSL (Wired)

9.1. Voice

9.1.1. PSTN/POTS Hierarchy Architecture Star Structure

9.2. Data

9.2.1. Symmetric SDSL ISDN DSL High Bit Rate DSL

10. FSO

10.1. Outdoor Deployment

10.1.1. Smog

10.1.2. Rain

10.1.3. Snow

10.2. Indoor Deployment

11. PLC (no new wires)

11.1. How?

11.1.1. Outdoor

11.2. Asymmetric

11.2.1. ADSL

11.2.2. VDSL

11.2.3. RADSL

11.2.4. G.Lite

11.3. Network Level?

11.3.1. Medium Voltage

11.3.2. High Voltage

11.3.3. Low Voltage

11.3.4. In Home

11.4. Modulation Scheme?

11.4.1. OFDM Definition The main concept of OFDM is orthogonality of the sub-carriers. The orthogonality allows simultaneous transmission on a lot of sub-carriers in a tight frequency space without interference from each other. Advantages i.) can easily adapt to severe channel conditions without complex time dome equalization ii) Robust against narrow-band co-channel interference iii) Robust against intersymbol interference (ISI) and fading cause by multipath propagation. iv) High spectral efficiency v) Low sensitivity to time synchronization errors. Disadvantages i) High peak-to-average-power-ratio (PAPR), requiring linear transmitter circuitry, which suffer from poor power efficiency. ii) Sensitive to frequency synchronization problem iii) Loss efficiency caused by cyclic prefix iv) Sensitive to Doppler shift

11.5. Channel?

11.5.1. Shared channel like Wifi

11.6. Protocols?

11.6.1. X-10

11.6.2. CE-Bus

11.6.3. Lon-Works

11.6.4. Home Plug 1.0

11.6.5. Home Plug AV

12. Duplexing

12.1. Time division duplexing (TDD)

12.2. Frequency division duplexing (FDD)

13. Multiple Access

13.1. Frequency Division Multiple Access (FDMA)

13.1.1. One circuit per channel at a time

13.1.2. Channel is normally narrow bandwidth (30kHz for AMPS)

13.1.3. Transceiver complexity is lower compared to TDMA

13.1.4. Fewer overhead bits

13.2. Time Division Multiple Access (TDMA)

13.2.1. TDMA is a multiplexing method that divides network connections into time slices. The TDMA digital transmission scheme multiplexes three signal over a single channel Often used to refer digital mobile phone networks TDMA allows many users to access a single RF channel without interference by allocating unique time slots to each user within each channel.

13.2.2. TDMA Advantages To increase the efficiency of transmission Can be easily adapted to the transmission of data as well as voice communication Most cost effective technology for upgrading analog to digital It is the only technology that offers an efficient utilization of hierarchal cells structures like pico, micro and macro cells.

13.2.3. TDMA Disadvantages Each user has a predefined time slot. It is subjected to multipath distortion.

13.2.4. How TDMA Works It relies upon the fact that the audio signal has been digitized where it divided into a number of ms-long packets. It allocates a single frequency channel for a short time and then moves to another channel The digital samples, from a single transmitter occupy different time slots in several bands at the same time

13.3. Orthogonal Frequency Division Multiple Access (OFDMA)

13.3.1. OFDMA is a multi-user version of the popular orthogonal frequency-division multiplexing digital modulation scheme.

13.3.2. Advantages of OFDMA is the deployment is flexible across many frequency bands with few modification to the air interfaces. It is also uses allocation with cyclic permutation which only has average interference within the cell. Furthermore, it is provides frequency diversity just by spreading the carriers all over the used spectrum. It also offers per-channel or per-subchannel power.

13.4. Spread Spectrum Multiple Access

13.4.1. Frequency Hoped Multiple Access (FHMA) The frequency can be adjusted in a pseudorandom sequence between several discrete radio channels Various user can use same spectrum Slow frequency hopping system if rate of change of carrier frequency is lower than symbol rate Fast frequency hopping system if rate of change of carrier frequency greater than symbol rate Example: Bluetooth & HomeRF

13.4.2. Direct sequence spread spectrum multiple access (DSSS) / code division multiple access (CDMA)

13.5. Pure ALOHA

13.5.1. Does not require slots

13.5.2. Send a frame whenever there is a frame

13.5.3. Does not require global time synchronization

13.5.4. Vulnerable time of 2 x Tfr

13.5.5. Throughput is reduced by one half. e.g : S=(1/2e)

13.6. Slotted ALOHA

13.6.1. Invented to improve efficiency of Pure ALOHA

13.6.2. Require slot synchronization

13.6.3. Send frame only at the beginning of the time slot

13.6.4. Detect collision slotted if multiple nodes transmit

13.6.5. Does require global time synchronization

13.6.6. Divide time into slot Tfr

13.6.7. Throughput for slotted ALOHA is S = G x G-e

14. Bit Error Rate (BER)

14.1. Number of bit error

14.2. Error rate per unit time of the received bits.

14.3. One of the key parameters as assessment

14.4. Factors affecting BER

14.4.1. Interference

14.4.2. Increase transmitter power

14.4.3. Lower order modulation

14.4.4. Reduce bandwidth

14.5. Formula-->> Number of error / Total bits sent

15. WiMAX Quality of Services (QoS) Classes

15.1. Unsolicited Grant Service (UGS)

15.1.1. support real-time data stream issued at periodic interval

15.1.2. Example : VoIP

15.2. Real-time Polling Services (rtPS)

15.2.1. support real-time streams consisting variable-sized data packet

15.2.2. Example : MPEG video

15.3. Non real-time Polling services (nrtPS)

15.3.1. support delay-tolerant data streams consisting of variable-size data packets for a minimum data rate required

15.3.2. If the hub fails, whole network is stopped

15.3.3. Example : FTP transmission

15.4. Parameter used to describe WiMAX QoS

15.4.1. Latency Measure in time delay in a system : time taken from initiation of sending data until it arrives its destination

15.4.2. Jitter Measure of the variability over time of the packet latency across a network

15.4.3. Packet Loss indicate the loss of data packets during transmission over a network

16. Network Topology

16.1. Star Topology

16.1.1. Pros Low network traffic Easy to troubleshoot Easy to setup and modify

16.1.2. Cons High installation cost Expensive to use

16.2. Mesh Topology

16.2.1. Pros Each connection can carry its own data load. Fault is diagnosed easily Provides security and privacy

16.2.2. Cons Installation and configuration are difficult High cabling cost

16.3. Ring Topology

16.3.1. Pros Cheap to install and expand Transmitting network is not affected by high traffic or by adding more nodes

16.3.2. Cons Troubleshooting is difficult in ring topology. Failure of one computer disturbs the whole network.

16.4. Wireless Mesh Network

16.4.1. Working Principle Self-Configuring Network automatically incorporates a new node into the existing structure without needing any adjustments by a network administrator Self-Healing Network automatically finds the fastest and most reliable paths to send data, even if nodes are blocked or lose their signal

16.4.2. Application Hospitality Warehouse Education Campus

17. Radio over Fiber (RoF)

17.1. Two main categories

17.1.1. RF-over Fiber

17.1.2. IF-over-Fiber

17.2. Advantages

17.2.1. Low attenuation

17.2.2. Low cost

17.2.3. Large bandwidth

17.2.4. Future proof

17.3. Challenges

17.3.1. Modulation technique

17.3.2. Chromatic dispersion

17.3.3. Phase distortion

17.3.4. High data rate wireless link as a complimentary part of RoF

17.3.5. Expensive and complex uplink

17.3.6. Noise characterization and cancellation for combination of optical and wireless noise

17.4. Application

17.4.1. Access to dead zones

17.4.2. FTTA (fiber to the antenna)

17.5. Current technologies by using RoF

17.5.1. IF over SMF and MMF

17.5.2. RF over SMF

18. WLAN

18.1. WIreless Local Area Network

18.1.1. uses radio waves as its carrier

18.1.2. IEEE 802.11 standard

18.1.3. covers Physical and Data Link Layers

18.2. Access Point (AP)

18.2.1. act as bridge between Wireless and Wired Network

18.2.2. provides access to the Distribution System (DS)

18.3. WLAN Topology

18.3.1. Infrastructure Mode Mobile stations (MS) is connected to AP AP is connected to wired network

18.3.2. Ad-Hoc Mode No AP required A number of MS form a cluster to make a network

18.4. How it works?

18.4.1. using the same networking protocols and supporting most of the same applications.

18.4.2. specialized physical and data link protocol

18.4.3. integrate into existing network through AP which provide a bridging function

18.4.4. stay connected as it roam from one coverage area to another

18.5. advantages

18.5.1. Mobility:

18.5.2. Fast setup

18.5.3. Higher cost

18.5.4. Expandability

18.6. Disadvantages

18.6.1. Interference

18.6.2. Inconsistent connections

18.6.3. Uses more power consumption

18.6.4. Lower speed

19. Free Space Optics (FSO)

19.1. Definition

19.1.1. Also called Free Space Photonics (FSP) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the atmosphere to obtain optical communications.

19.2. How does it works?

19.2.1. Uses laser technology to send optical signals through the air using lenses and mirrors to focus and redirect the beams and send data from one chip to another. Consists of optical transmitter and receiver

19.3. Advantages

19.3.1. no interference

19.3.2. Does not require spectrum license

19.3.3. Installation cost is lower compared to laying Fiber

19.3.4. Low power consumption

19.3.5. easily upgradeable

19.4. Disadvantage

19.4.1. support only point to point communication

19.4.2. atmospheric attenuation

19.4.3. scintillation

19.4.4. signal scattering results in multipath impairment

19.4.5. susceptible to loss & natural impediment (rain, haze, fog, obstruction)

20. Optical Fiber Technology

20.1. Definition

20.1.1. medium and the technology associated with the transmission of information as light pulses along a glass or plastic strand or fiber

20.2. Working Principle

20.2.1. Transmit data in the form of light particles or photons that pulse through a fiber optic cable using the process called total internal reflection

20.3. Types of Fibers

20.3.1. SMF Definition Single Mode Fiber optic cable has a small diameter core that allows only one mode of light to propagate Advantages Increase bandwidth capacity Better performance in long runs transmission Limited Data Dispersion & External Interference Fast transmission speed Disadvantages High cost Application Best choice for transmitting data over long distance Used for connections over large areas such as college, campuses and remote offices

20.3.2. MMF Definition Multimode Fiber optic cable has a large diametral core that allows multiple mode of light to propagate Advantages Less expensive Easier to work with other optical components Allows several mode optical signals transmitted at the same time Good alignment tolerances due to large fiber core Disadvantages High dispersion and attenuation rate Applications Good choice for transmitting data and voices signals over shorter distance Used for data and audio/visual application in local area networks and connections within buildings or remote office in close proximity to one another.


21.1. signal travels over the air directly from a wireless transmitter to a wireless receiver without passing an obstruction.

21.1.1. reach longer distance with better signal strength and higher throughput

21.1.2. example of LOS Microwave point to point communication point to point connection between BS and SS.

21.1.3. Application Building to building connectivity Fiber line replacement Wireless failover

21.2. Opposite to NLOS

21.2.1. NLOS- signal from a wireless transmitter passes several obstructions before arriving at a wireless receiver. example of NLOS Wireless connection between BS (Base Station) and SS (Subscriber station) application Public Wi-Fi Campus wide broadband Locations that can't be cabled Stadiums and exhibitions halls WiMAX

21.3. LOS vs NLOS

21.3.1. similarities operate in both unlicensed and licensed frequencies bands.

21.3.2. difference LOS point to point NLOS point to multipoint

22. HFC Network

22.1. Why used HFC

22.1.1. To carry broadband contents (Video, Audio, Data)

22.1.2. Increase Transmission Range

22.1.3. Maintain Superior performance

22.2. Advantages

22.2.1. Reduce power consumption

22.2.2. Simplification of the maintainance

22.2.3. Increase RF bandwidth

22.2.4. Improve Reliability

22.2.5. Improve QoS and potential terminal cost reduction

22.3. Disadvantages

22.3.1. Not fully installed

22.3.2. Expensive

23. WMAN

23.1. WHAT IS WMAN ??

23.1.1. - Short form from Wireless Metropolitan Area Network - Connection of several WLAN - Has an intended coverage are Two types of WMAN Back Haul Last Mile

23.2. Underwater FSO

23.2.1. Definition FSO underwater is an optical communication technology that utilized the use of laser diode or light emitting diode, LED to transmit or receive data information, voice and video through underwater

23.2.2. Current Technology Optical wireless Acoustic wave Radio Frequency

23.2.3. Medium Laser Diode Long Distance Low Spectral Width High Data Rate Transmission High Output Power High Operating Cost Light Emitting Diode LED Short Distance High Spectral Width Low Data Rate Transmission Low Output Power Low operating cost

23.2.4. Features FSO System Length 50-150 m Attenuation 0.39-11.0 db/m Bandwidth 0.8 nm Operating Wavelength 405 nm

23.2.5. Advantages High Data Transmission Lower Attenuation Easy to install Lower Error Rate


23.3.1. An outdoor, point to point WLAN


23.4.1. ADVANTAGES - Simple and easy to distinguish - Less costing than fiber-based LANs

23.4.2. DISADVANTAGES - Large area for hacker to attempt a break in


23.5.1. Security Vulnerability No two way authentication Weak curyptographic Reuse TEK

24. Fttx (Fiber To The X)

24.1. Definitions

24.1.1. All possible optical fiber topologies from a telecom or cable carrier to its customers, based on the location of the fiber's termination point. FTTP/FTTH/FTTB (Fiber laid all the way to the premises/home/building) FTTC/N (fiber laid to the cabinet/node, with copper wires completing the connection)

24.2. Advantages

24.2.1. the demand for reliable bandwidth is crucial as more and more people begin to utilize these services.

24.2.2. Fibre to the All it mean we can provide any services Ex: Business, House, Buildings.

24.2.3. It has good speed and quality of net.

24.2.4. Fiber is often said to be "future-proof" because the data rate of the connection is usually limited by the terminal equipment rather than the fiber

24.3. Disadvantages

24.3.1. Installation costs, while dropping, are still high

24.3.2. Susceptibility to physical damage

24.4. Deployment of Fttx in Malaysia

24.4.1. Telekom Malaysia (TM) officially launched FTTH on 24 March 2010.

24.4.2. TM High Speed Broadband (HSBB) was released to end users in stages.

24.4.3. The deployment from start to the connection of the first end user to the fiber network took only 18 months, which is the fastest ever in the world.

24.4.4. The product name is UniFi and it initially offers speeds of 5, 10 and 20 Mbit/s under the VIP5, VIP10 and VIP20 brand name.The packages were later revised to UniFi Advance (30 and 50Mbit/s) and UniFi Pro (100Mbit/s).

24.4.5. The fiber network is also leased out to competitors Maxis Communications and Packet One Networks.

24.4.6. TIME Fibre Broadband which is Officially launched on 2 February 2010 is a true fibre optic connectivity to home with speeds of 100Mbit/s, 300Mbit/s, 500Mbit/s. Time offer the FTTx services to the apartment Condominium residential only.

25. Ethernet Passive Optical Network (EPON)

25.1. How does an EPON work?

25.1.1. In a EPON the process of transmitting data downstream from the OLT to multiple ONUs is fundamentally different from transmitting data upstream multiple ONUs to the OLT.

25.2. What Are EPON?

25.2.1. Ethernet passive optical networks (EPON) are an emerging access network technology that provides a low-cost method of deploying optical access lines between a carrier office (CO) and customer site

25.3. Downstream Traffic flow in an EPON

25.3.1. The data broadcasted downstream from OLT to multiple ONUs in variable-length packets of up to 1,518 bytes, according to IEEE 802.3 protocol. Each packet carries a header that uniquely identifies it as data intended for ONU-1, ONU-2 or ONU-3.At the splitter the traffic is divided into three separate signals, each carrying all of the ONU specific packets. When the data reaches the ONU, it accepts the packets that are intended for it and discards the packets that are intended for other ONUs. For example, ONU-1 receives packets 1, 2 and 3; however only two packets are delivered to end user 1

25.4. Upstream Traffic flow in an EPON

25.4.1. The upstream traffic is managed utilizing TDM technology, in which transmission time slots are dedicated to ONUs. The time slots are synchronized so that upstream packets from the ONUs do not interfere with each other one the data is couple onto the common fiber. For example, ONU-1 transmits packet 1 in the first time slot, ONU-2 transmits packet 2 in the second non-overlapping time slot , and ONU-3 transmits packet 3 in a third non-overlapping time slot. Consider the downstream traffic in EPON.

25.5. Benefits of EPON

25.5.1. Higher bandwidth : up to 1.25 Gbps symmetric Ethernet bandwidth More subscribers per PON More bandwidth per subscriber Higher split counts Video capabilities Better QoS

25.5.2. Lower Costs: lower up-front capital equipment and ongoing operational costs Cost reduction in the case of EPONs are achieved by simpler architecture, more efficient operations, and lower maintenance needs of an optical IP Ethernet network Eliminate complex and expensive ATM and SONET elements and dramatically simplify the network architecture Long-lived passive optical components reduce outside plant maintenance Standard Ethernet interfaces eliminate the need for additional DSL or cable modems No electronics in outside plant reduces need for costly powering and right-of-way space

25.5.3. More revenue : broad range of flexible service offerings means higher revenues EPONs support for legacy TDM , ATM and SONET services. Delivery of new Gigabit Ethernet, fast Ethernet, IP multicast and dedicated wavelength services Provisioning of bandwidth in scalable 64 Kbps increments up to 1 Gbps. Tailoring of services to customer needs with guaranteed SLAs (Service License Agreement) Quick response to customer needs with flexible provisioning and rapid service reconfiguration.

26. FiWi Network

26.1. Free Space Optics (FSO)

26.1.1. Working Principle Deploying either a high-power light emit-ting diode(LED) or a laser diode, while the receiver may deploy a simple photo detector

26.1.2. Importance FSO offers high bandwidth and reliable communication over short distance convenience High speed Security

26.2. Radio over Fiber (RoF)

26.2.1. Working Principle Light is amplitude modulated by a radio signal and transmitted over an optical fiber link to facilitate wireless access

26.2.2. Importance Low attenuation Loe complexity Low cost Future proof

27. CWDM


27.1.1. a method of combining multiple signals on laser beams at various wavelengths for transmission along fiber optic cables

27.2. Transmission using 18 channels (1270 - 1610 nm)


27.3.1. supports up to 18 wavelength channels

27.3.2. wavelength chosen from 1270 nm to 1610 nm

27.3.3. channel spacing 20 nm apart

27.3.4. cost-efficient solution for shorter distances of up to 70 kilometers.


27.4.1. high optical fiber transmission capacity

27.4.2. small volume, low power consumption

27.4.3. good flexibility and expansibility

27.4.4. improve business quality


27.5.1. Less channel count

27.5.2. large channel spacing

27.5.3. low bandwidth compared to DWDM

28. DWDM

28.1. Definition

28.1.1. up to 80 (and theoretically more) separate wavelengths or channels of data can be multiplexed into a light stream transmitted on a single optical fiber.

28.2. DWDM System Components

28.2.1. Optical Transmitters/Receivers

28.2.2. DWDM Mux/DeMux Filters

28.2.3. ptical Add/Drop Multiplexers (OADMs)

28.2.4. Optical Amplifiers

28.2.5. Transponders (Wavelength Converters)

29. GPON vs HFC

29.1. Similarity

29.1.1. system use same RF video transmitter

29.2. Differences

29.2.1. System

29.2.2. Operating & Maintenance Costs

29.2.3. Bandwidth

29.3. Advantages of GPON over HFC

29.3.1. Smaller node size

29.3.2. Reduce operations and maintenance costs

29.3.3. Great transmission capacity with dedicated wavelengths for:- Upstream, Downstream Downstream cable-TV overlay

30. Peer to Peer Network

30.1. Advantages

30.1.1. Low cost

30.1.2. Simple to configure

30.1.3. User has full accessibility of computer

30.2. Disadvantages

30.2.1. May have duplication in resources

30.2.2. Difficult to uphold security policy.

30.2.3. Difficult to handle uneven loading

30.3. Where p2p network is appropriate

30.3.1. 10 or less user

30.3.2. No specialized service required

30.3.3. Security is not an issue

30.3.4. Only limited growth foreseeable future

31. Power Line Communication[ PLC ]

31.1. Definition

31.1.1. Uses electrical wiring to simultaneously carry both data and electric power

31.1.2. Systems operate by impressing a modulated carrier signal on power wires

31.2. Important of PLC

31.2.1. Usage of the power grid for control, maintenance and charging purposes by the utility commodities

31.2.2. Liberalization of telecommunication

31.2.3. New dimensions to the potential application of the electricity infrastructure

31.2.4. Growth of the internet has accelerated the demand for digital telecommunications services to almost every premises

31.3. Issues of the system

31.3.1. Impedance, considerable noise, and high attenuation

31.3.2. Electromagnetic Compatibility (EMC)

31.3.3. Transmission of data rate at Low Voltage to many subscribers also reduces the performances of data rate

31.4. Advantages

31.4.1. Allows consumers to use their already existing electrical wiring systems to connect home appliances to each other and to the Internet

31.4.2. Equalization is perfect High-resolution digital filtering gives very flat filter response as desired

31.4.3. Processing is accurate and reliable

31.5. Disadvantages

31.5.1. Improper performance especially in long distances and in high noise environment

31.5.2. High costs of residential appliances

31.5.3. Lack of global standards

32. WiMAX

32.1. definition

32.1.1. Worldwide Interoperability for Microwave Access is a technology standard for long-range wireless networking, for both mobile and fixed connections.

32.2. elements

32.2.1. Base Station

32.2.2. Subscriber station

32.3. pros & cons

32.3.1. pros Higher coverage range cheaper alternative to broadband wired technologies

32.3.2. cons LOS high speed voice and data transfer over longer distances. power consuming technology and requires significant electrical support higher initial costs and higher operational costs

32.4. differences between WiMAX and WLAN(WiFi)

32.4.1. WLAN can deliver much faster speeds compared to WiMAX

32.4.2. WiMAX is meant for long range applications while WLAN is meant for short range applications.

32.4.3. WiMAX provides a much better method of bandwidth distribution compared to WLAN.