Access Network Technologies

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Access Network Technologies by Mind Map: Access Network Technologies


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

2. Added Bandwidth Distribution and Protection


3.1. cable television networks

3.2. metropolitan networks


4.1. WiMAX

4.2. LTE

5. Performance

5.1. High-speed

5.2. High-sensitivity

6. Pseudorandom binary sequence (PRBS)

7. provides network connectivity over wireless media

8. BER Testing

8.1. Quasi-random signal source (QRSS):


9.1. XG-PON

9.1.1. G.987.1

9.1.2. 10Gbps downstream & 2.48Gbps for upstream

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

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

10. FTTx

10.1. PON

10.1.1. APON Built on ATM

10.1.2. BPON

10.1.3. EPON Uses Ethernet Packet

10.1.4. GPON High Speed and Power Saving

11. DSL (Wired)

11.1. Voice

11.1.1. PSTN/POTS Hierarchy Architecture Star Structure

11.2. Data

11.2.1. Symmetric SDSL ISDN DSL High Bit Rate DSL

12. FSO

12.1. Outdoor Deployment

12.1.1. Smog

12.1.2. Rain

12.1.3. Snow

12.2. Indoor Deployment

13. PLC (no new wires)

13.1. How?

13.1.1. Outdoor

13.2. Asymmetric

13.2.1. ADSL

13.2.2. VDSL

13.2.3. RADSL

13.2.4. G.Lite

13.3. Network Level?

13.3.1. Medium Voltage

13.3.2. High Voltage

13.3.3. Low Voltage

13.3.4. In Home

13.4. Modulation Scheme?

13.4.1. 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

13.5. Channel?

13.5.1. Shared channel like Wifi

13.6. Protocols?

13.6.1. X-10

13.6.2. CE-Bus

13.6.3. Lon-Works

13.6.4. Home Plug 1.0

13.6.5. Home Plug AV

14. Duplexing

14.1. Time division duplexing (TDD)

14.2. Frequency division duplexing (FDD)

15. Multiple Access

15.1. Frequency Division Multiple Access (FDMA)

15.1.1. One circuit per channel at a time

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

15.1.3. Transceiver complexity is lower compared to TDMA

15.1.4. Fewer overhead bits

15.2. Time Division Multiple Access (TDMA)

15.2.1. 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.

15.2.2. 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.

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

15.2.4. 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

15.3. Orthogonal Frequency Division Multiple Access (OFDMA)

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

15.3.2. 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.

15.4. Spread Spectrum Multiple Access

15.4.1. 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

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

15.5. Pure ALOHA

15.5.1. Does not require slots

15.5.2. Send a frame whenever there is a frame

15.5.3. Does not require global time synchronization

15.5.4. Vulnerable time of 2 x Tfr

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

15.6. Slotted ALOHA

15.6.1. Invented to improve efficiency of Pure ALOHA

15.6.2. Require slot synchronization

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

15.6.4. Detect collision slotted if multiple nodes transmit

15.6.5. Does require global time synchronization

15.6.6. Divide time into slot Tfr

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

16. Bit Error Rate (BER)

16.1. Number of bit error

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

16.3. One of the key parameters as assessment

16.4. Factors affecting BER

16.4.1. Interference

16.4.2. Increase transmitter power

16.4.3. Lower order modulation

16.4.4. Reduce bandwidth

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

17. WiMAX Quality of Services (QoS) Classes

17.1. Unsolicited Grant Service (UGS)

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

17.1.2. Example : VoIP

17.2. Real-time Polling Services (rtPS)

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

17.2.2. Example : MPEG video

17.3. Non real-time Polling services (nrtPS)

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

17.3.2. If the hub fails, whole network is stopped

17.3.3. Example : FTP transmission

17.4. Parameter used to describe WiMAX QoS

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

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

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

18. Network Topology

18.1. Star Topology

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

18.1.2. Cons High installation cost Expensive to use

18.2. Mesh Topology

18.2.1. Pros Each connection can carry its own data load. High cabling cost Fault is diagnosed easily Provides security and privacy

18.2.2. Cons Installation and configuration are difficult

18.3. Ring Topology

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

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

18.4. Wireless Mesh Network

18.4.1. 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

18.4.2. Application Hospitality Warehouse Education Campus

19. Radio over Fiber (RoF)

19.1. Two main categories

19.1.1. RF-over Fiber

19.1.2. IF-over-Fiber

19.2. Advantages

19.2.1. Low attenuation

19.2.2. Low cost

19.2.3. Large bandwidth

19.2.4. Future proof

19.3. Challenges

19.3.1. Modulation technique

19.3.2. Chromatic dispersion

19.3.3. Phase distortion

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

19.3.5. Expensive and complex uplink

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

19.4. Application

19.4.1. Access to dead zones

19.4.2. FTTA (fiber to the antenna)

19.5. Current technologies by using RoF

19.5.1. IF over SMF and MMF

19.5.2. RF over SMF

20. WLAN

20.1. WIreless Local Area Network

20.1.1. uses radio waves as its carrier

20.1.2. IEEE 802.11 standard

20.1.3. covers Physical and Data Link Layers

20.2. Access Point (AP)

20.2.1. act as bridge between Wireless and Wired Network

20.2.2. provides access to the Distribution System (DS)

20.3. WLAN Topology

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

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

20.4. How it works?

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

20.4.2. specialized physical and data link protocol

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

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

20.5. advantages

20.5.1. Mobility:

20.5.2. Fast setup

20.5.3. Higher cost

20.5.4. Expandability

20.6. Disadvantages

20.6.1. Interference

20.6.2. Inconsistent connections

20.6.3. Uses more power consumption

20.6.4. Lower speed

21. Free Space Optics (FSO)

21.1. Definition

21.1.1. 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.

21.2. How does it works?

21.2.1. 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

21.3. Advantages

21.3.1. no interference

21.3.2. Does not require spectrum license

21.3.3. Installation cost is lower compared to laying Fiber

21.3.4. Low power consumption

21.3.5. easily upgradeable

21.4. Disadvantage

21.4.1. support only point to point communication

21.4.2. atmospheric attenuation

21.4.3. scintillation

21.4.4. signal scattering results in multipath impairment

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

22. Optical Fiber Technology

22.1. Definition

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

22.2. Working Principle

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

22.3. Types of Fibers

22.3.1. 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

22.3.2. 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.


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

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

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

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

23.2. Opposite to NLOS

23.2.1. 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

23.3. LOS vs NLOS

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

23.3.2. difference LOS point to point NLOS point to multipoint

24. HFC Network

24.1. Why used HFC

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

24.1.2. Increase Transmission Range

24.1.3. Maintain Superior performance

24.2. Advantages

24.2.1. Reduce power consumption

24.2.2. Simplification of the maintainance

24.2.3. Increase RF bandwidth

24.2.4. Improve Reliability

24.2.5. Improve QoS and potential terminal cost reduction

24.3. Disadvantages

24.3.1. Not fully installed

24.3.2. Expensive

25. WMAN

25.1. WHAT IS WMAN ??

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

25.2. Underwater FSO

25.2.1. 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

25.2.2. Current Technology Optical wireless Acoustic wave Radio Frequency

25.2.3. 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

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

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


25.3.1. An outdoor, point to point WLAN


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

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


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

26. Fttx (Fiber To The X)

26.1. Definitions

26.1.1. 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)

26.2. Advantages

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

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

26.2.3. It has good speed and quality of net.

26.2.4. 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

26.3. Disadvantages

26.3.1. Installation costs, while dropping, are still high

26.3.2. Susceptibility to physical damage

26.4. Deployment of Fttx in Malaysia

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

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

26.4.3. 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.

26.4.4. 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).

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

26.4.6. 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.

27. Ethernet Passive Optical Network (EPON)

27.1. How does an EPON work?

27.1.1. 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.

27.2. What Are EPON?

27.2.1. 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

27.3. Downstream Traffic flow in an EPON

27.3.1. 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

27.4. Upstream Traffic flow in an EPON

27.4.1. 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.

27.5. Benefits of EPON

27.5.1. 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

27.5.2. 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

27.5.3. 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.

28. FiWi Network

28.1. Free Space Optics (FSO)

28.1.1. 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

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

28.2. Radio over Fiber (RoF)

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

28.2.2. Importance Low attenuation Loe complexity Low cost Future proof

29. CWDM

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


29.2.1. supports up to 18 wavelength channels

29.2.2. wavelength chosen from 1270 nm to 1610 nm

29.2.3. channel spacing 20 nm apart

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


29.3.1. high optical fiber transmission capacity

29.3.2. small volume, low power consumption

29.3.3. good flexibility and expansibility

29.3.4. improve business quality


29.4.1. Less channel count

29.4.2. large channel spacing

29.4.3. low bandwidth compared to DWDM

30. DWDM

30.1. Definition

30.1.1. 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.

30.2. DWDM System Components

30.2.1. Optical Transmitters/Receivers

30.2.2. DWDM Mux/DeMux Filters

30.2.3. ptical Add/Drop Multiplexers (OADMs)

30.2.4. Optical Amplifiers

30.2.5. Transponders (Wavelength Converters)

31. GPON vs HFC

31.1. Similarity

31.1.1. system use same RF video transmitter

31.2. Differences

31.2.1. System Bandwidth

31.2.2. Operating & Maintenance Costs

31.3. Advantages of GPON over HFC

31.3.1. Smaller node size

31.3.2. Reduce operations and maintenance costs

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

32. Peer to Peer Network

32.1. Advantages

32.1.1. Low cost

32.1.2. Simple to configure

32.1.3. User has full accessibility of computer

32.2. Disadvantages

32.2.1. May have duplication in resources

32.2.2. Difficult to handle uneven loading

32.2.3. Difficult to uphold security policy.

32.3. Where p2p network is appropriate

32.3.1. 10 or less user

32.3.2. No specialized service required

32.3.3. Security is not an issue

32.3.4. Only limited growth foreseeable future

33. Power Line Communication[ PLC ]

33.1. Definition

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

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

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

33.2. Important of PLC

33.2.1. Liberalization of telecommunication

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

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

33.3. Issues of the system

33.3.1. Impedance, considerable noise, and high attenuation

33.3.2. Electromagnetic Compatibility (EMC)

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

33.4. Advantages

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

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

33.4.3. Processing is accurate and reliable

33.5. Disadvantages

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

33.5.2. High costs of residential appliances

33.5.3. Lack of global standards

34. WiMAX

34.1. definition

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

34.2. elements

34.2.1. Base Station

34.2.2. Subscriber station

34.3. pros & cons

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

34.3.2. 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

34.4. differences between WiMAX and WLAN(WiFi)

34.4.1. WLAN can deliver much faster speeds compared to WiMAX

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

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