suguru yamaguchi nara institute of science and technology

Suguru Yamaguchi Nara Institute of Science and Technology

Information Science and Technology

情報ネットワーク論I / 第4回 1

 ATM: Challenge to integrate circuit switching and packet switching

 Another main datalink technology  Current status of IEEE802.3  IEEE802.15~


 Wide band datalink technology started to develop and standardize in the late 1980s –  150Mbp (OC-3), 662Mbps (OC-12) were target

 ATM: Asynchronous Transfer Mode  High speed transfer enabling to exchange static 53

octets cell. –  Cut-through switching based on hardware –  Low delay link

 Enables to have both characteristics of packet switching and circuit switching –  VP (Virtual Path) and VC (Virtual Circuit) –  ATM Adaptation Layer (AAL) defines services



VP: Setting by node/node, identified by VPI　

VC: belonging to one VP, setting by node/node and identified by VCI .

  Distinguishes logical network from physical network.

–  When viewing from network layer, ＶＰ/VC is thought single legacy physical circuit

–  Same as IEEE802.1q Tag VLAN 情報ネットワーク論I / 第4回 6

Logical topology


Physical Layer

ATM Layer

ATM Adaptation Layer (AAL)

Signaling Data Transmission

VC configuration

control

Data transmission I/F

•  Cell generation •  Cell multiplexing and demultiplexing •  Cell flow and order assignment management •  Dropped cell processing •  VC/VP based switch routing

Defines various service classes

 High-speed synchronous transmission line based on optical fiber –  SONET (Synchronous Optical Network) –  Fundamental technology based on digital optical

transmission network used by telephone companies –  OC (Optical Carrier level)

•  OC-3 155.52Mbps •  OC-12 622.08Mbps •  OC-24 1244.16Mbps •  OC-48 2488.32Mbps •  OC-192 10Gbps

 Recently, bandwidth speeding-up is remarkable. –  From OC-3 to OC-12 or OC-48, and further OC-192


 Interface Layer defined to use ATM network. –  AAL1

•  Constant bit rate transmission (e.g., graphics transmission.) –  AAL2

•  Variable bit rate transmission (e.g., movie transmission such as MPEG2)

–  AAL3/4 •  Packet transmission modeling •  Not in use

–  AAL5 •  Packet transmission model by ATM Forum •  Currently using in ATM computer networks.


 PVC (Permanent Virtual Circuit) –  Static VC configuration. –  Used in simple operation

 SVC (Switched Virtual Circuit) –  Dynamic VC configuration –  Used in LAN Emulation –  NBMA


 Used as a “wire” by PVC –  Setting an independent logical network on a physical

network structure. –  When optical fiber laying is limited, VC can be effectively

configured for management purpose.

 PVP generalization –  Path is statically set. –  VC is opened on the user side, and VC configuration is

enforced to comply to the usage purpose.


 Wide-area broadband service such as NTT MegaLink is deployed widely. –  ATM leased line service –  Effectively utilizing ATM’s characteristics

•  Cheaper than existing leased line in bit-per cost. •  Can reduce the number of connection devices depending on

VC usage. –  One interface can be assigned to several devices

•  But using Hardware is expensive –  Single Mode Fiber I/F is necessary –  Traffic shaper is necessary


 It emerged as the favorite wide-area bandwith service, but after, being slowly driven out by the extending Ethernet service system (ex LAN) might be a fair recognition. –  However, it is a formulation of the basic grounds for carrier

business as used to be. –  Outclassing compliance with management system in

telecommunication companies. –  Merit: deployable to various services. –  Finally, it is used to providing services upon an ATM

network, and directly providing ATM to the user is slowly decreasing.


  Broadband services using the carrier’s line –  Uses line between the subscriber station and the concentrator –  Data transmission is done using a frequency band different from

the band usually used for voice communication –  Relatively using wide bandwidth

 Many different variations –  ADSL: Asymmetric Digital Subscriber Line

•  Widely used broadband technology nowadays •  3Mbps, 8Mbps, 12Mbps

–  VDSL: Very high bit rate Digital Subscriber Line •  Appearing as the second-generation broadband access technologies •  25Mbps ~ 50Mbps

–  Unused technologies… •  SDSL: Symmetric Digital Subscriber Line •  HDSL: High bit rate Digital Subscriber Line



Telephone network

Ｉｎｔｅｒｎｅｔ

Department concentrator

Client

CPE

DSLAM aggregator

Switchboards concentrator

Data and voice are transmitted using the same medium

 Evolved as a Peripheral Bus –  HIPPI (800Mbps/32bit, 1.6Gbps/64bit) –  FibreChannel (FC) (266Mbps, …) –  Myrinet ( max 4Gbps) –  SCI (6.4Gbps and higher) –  IEEE1394 ( 100Mbps ～ 400Mbps): firewire

 Characteristics –  Synchronous Transfer, Error free, good delay characteristics（little jitter）

–  Changing from Parallel to Serial transfer. –  Changing from E I/F to Opt I/F. –  Reduction in its usage as a network

•  The Ethernet family range is rapidly widening


 Wave-Division Multiplex –  Technology taking advantage of the fact that several optical signals

of different wavelength can be transported in a single optical fiber to increase the range of possible uses without replacing the physical wire

•  e.g., SONET OC-48 –  Gained attention as a large-scale network broadband technology

•  especially, as a backbone network technology for communication companies •  bit inflation

–  Currently used WDM technology •  more than 16 waves: D-WDM (Dense WDM) •  8 waves: C-WDM (Coarse WDM) •  4 waves: W-WDM (Wide WDM)

–  Future WDM •  standardization of OIF (Optical Internetworking Forum)

–  Cisco, lucent, AT&T、NTT、Fujitsu, KDD lab, Ericson •  DWDM with more than 1024 waves •  from IP over ATM over SONET/SDH over WDM

to IP over WDM



OC48(2.4G), OC192(9.6G)…., OC768(40G)

16 waves 32waves 64waves

 Multi Protocol Label Switching –  An identifier called label is inserted between Layer-2 and

Layer-3 headers –  In MPLS networks, forwarding packets is done according to

the label.

 Characteristics –  At first, contribute to speeding up communications

•  It is not necessary to refer to the packet header. –  Emergence of various applications compliant to label based

traffic management •  Using labels, traffic is controlled under layer 3. •  Bandwidth assignment, optimal path for specific traffic, bypass,

 Adopted by large carriers and used in operation.


 Generalized MPLS –  Derived from Multi Protocol Lambda Switching –  Generalization of MPLS technology by using light wave as

the label.

 Managing GMPLS –  Routing based on optical wavelength. –  Using IP channel for transmitting a control signal.

 Starting to provide a communication service. –  RFC 3471~3473 (as standards) (Jan, 2003) –  Communication service

•  RENA (Resonant Communication Network Architecture, NTT) –  Confirming interoperability


 The so-called Wireless Ethernet –  802.11a: 54Mbps / 5.7GHz –  802.11b: 11Mbps / 2.4GHz –  802.11g: 50Mbps / 2.4GHz –  802.11n: 600Mbps / 2.4GHz,5GHz

 Efficient bandwidth usage leveraging SS technology.  Wi-Fi (Wireless Fidelity) is used as a trademark to brand

products.  Easiness of network usage and difficulty of network design

are two sides of the same coin. –  Enables invisible wireless. –  There is a radio wave interference in inter-802.11x –  There is a radio interference in some other wireless devices.

•  e.g., Bluetooth, microwave…


WG name topic 802.3z Gigabit Ethernet 802.3ab 1000Base-T 802.3ae 10Gbps Ethernet 802.3af DTE Power via MDI 802.3ah Passive Optical Network 802.3ak 10GBASE-CX4 802.3an 10GBASE-T 802.3aq 10GBASE-LRM 802.3at DTE Power Enhancements 802.3av 10Gbps PHY for EPON 802.3az Energy-efficient Ethernet 802.3ba 40Gbps and 100Gbps Ethernet

 Power supply via Ethernet –  Possible in IEEE 802.3af, but requires far more electric

power. –  Recently devices require far more electric power than IEEE

802.3af maximal capacity. •  802.3af 12.95W(Maximum) •  802.3at 24W(Minimum)

 802.3 is only supported by category 5 cables. –  802.3af is supported by both cat3 and cat5 –  802.3at is only supported by Category 5 because of low

electric resistance.

 Scheduled to be standardized in Feb. 2009.

 Applications requiring wider bandwidth. –  IPTV, VoD, VoIP… –  1G-EPON(Ethernet passive optical networks)(802.3ah) is

not sufficient.

 10G-EPON –  Enables symmetric and asymmetric communication. –  Because past technologies can be used, the shift is easy.

 Scheduled to be standardized in Mar. 2009.

 Saving electricity. –  If NIC communication speed is high, power consumption is

high. –  Reducing power consumption during infrequent

communication situations. •  Frequent usage case: bandwidth is1Gbps; infrequent usage

case: bandwidth is 100Mbps. •  Defining a switching mechanism that Seamlessly change from

1GBASE-T to 100BASE-T, and from 1GBASE-T to 10BASE-T.

 Scheduled to be standardized in Mar. 2010.

 Supporting two transmission speeds: 40Gbps and 100Gbps. –  For carriers: 100Gbps

•  Having a 10 km single mode fiber and 1m coax –  For datacenters: 40Gbps

•  Having a 40km single mode fiber and 10m coax

 Scheduled to be standardized in Jun. 2010.

Working Group

IEEE802.15 Wireless Personal Area Networks

IEEE802.16 Broadband Wireless Access Standards

IEEE802.17 Resilient Packet Ring

IEEE802.18 Radio Regulatory TAG

IEEE802.19 Coexistence Technical Advisory

IEEE802.20 Mobile Broadband Wireless Access

IEEE802.21 Media Independent Handover

IEEE802.22 Wireless Regional Area Networks

IEEE802.23 emergency service


 IEEE 802.15 (Wireless Personal Area Networks) –  Summary

•  Personal area wireless network –  Concrete example

•  Bluetooth（IEEE 802.15.1） –  Logical and physical specifications –  Profile for various communication types

•  UWB（IEEE 802.15.13a） –  Wide bandwidth –  Bandwidth allocation problem

•  ZigBee（IEEE 802.15.4） –  Low power consumption


  IEEE 802.16 (Broadband Wireless Access Standards) –  Summary

•  Metropolitan Area Network –  Characteristics

•  Frequency：75 MHz •  Cell radius：10km (in the case of high power consumption at high locations, the maximum is 50km) •  Supporting high speed transportation (120km/h) •  It covers both MAC and PHY layers

–  Concrete example •  static WiMAX (IEEE 802.16-2004) •  mobile WiMAX (IEEE 802.16e)

–  Trends •  Discussion has started for IEEE802.16m (4G requirement),

IEEE802.16n (Higher Reliability Networks), and IEEE802.16p (Machine-to-Machine Applications).


 IEEE802.17 (Resilient Packet Ring) –  Summary

•  Combines reliability , service quality guarantee and management features to packet network statistical efficiency for SONET （Synchronous Optical NETwork）

–  Concrete example •  Spatially Aware Sublayer (802.17b)

 IEEE 802.18 (Radio Regulatory TAG) –  Summary

•  Technical assistance for wireless communications.

 IEEE 802.19 (Coexistence Technical Advisory) –  Summary

•  Technical Assistance for standard Coexistence.


 Mobile Broadband Wireless Access –  Summary

•  Metropolitan Area Network –  Characteristics

•  Enforcing transmission error correction with Fast ARQ (Automatic Repeat Request)

•  Handover policy is “make before break” •  IP roaming & handoff at more than 1 Mbps •  Better frequent use efficiency than IEEE802.11e •  Optimized for full mobility up to vehicular speeds of 250 km/h •  Operates in Licensed Bands below 3.5 GHz


 IEEE 802.21 –  Summary

•  Implementing handover technology. –  Characteristics

•  Defining a MIH(Media Independent Handover) between layer2 and layer3.

•  Enforcing a seamless handover among WiFi, WiMAX, and cellular


 Wireless Regional Area Network (WRAN) –  Summary

•  Network service for rural area –  Characteristics

•  Point to Multipoint static wireless access method •  Using unused spectrum of TV Broadcast Service to bring

broadband access to the rural area


802.15

802.11

802.16 802.20

802.22

WPAN

WWAN WMAN WLAN

 IEEE 802.23 –  Summary

•  Aiming to use emergency service (emergency call, 110 number service in Japan) with IEEE802 networks.

–  Characteristics •  Using VoIP (Voice over Internet Protocol) •  Four domains of application

–  Citizen to Authority (emergency call from citizen, for example 110 and 119 in Japan)

–  Authority to Citizen (emergency broadcast warning from governance office to citizen)

–  Authority to Authority (emergency wireless ad hoc network) –  Citizen to Citizen (ETSI requirements)


Wi-Fi WiMAX

Protocol IEEE802.11a IEEE802.11b IEEE802.11g IEEE802.11n IEEE802.16-2004 IEEE802.16e

Max range 0.015km 0.025km 0.025km 0.05km 10km 3km

Max data rate 54Mbps 11Mbps 54Mbps 600Mbps 74.81Mbps 21Mbps

Band Width 5MHz 10MHz 20MHz 5MHz 5MGz 20MHz 40MHz 1.5~20MHz 1.25~20MHz

Frequency 5.2GHz 2.4GHz 2.4GHz 2.4GHz 5GHz 2.5GHz 3.5GHz 5.8GHz

2.5GHz

suguru yamaguchi nara institute of science and technology

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