wireless mesh network technical overview

Wireless Mesh NetworkWireless Mesh Network

Technical OverviewTechnical Overview

Danny Ngmailto:[email protected]

2

What is a Wireless Mesh Network ?What is a Wireless Mesh Network ?

AccessPoint

AccessPoint

Backbone Ethernet Network

IEEE 802.11 a/b/g

10/100BT Ethernet

Traditional WLAN Architecture

3


AccessPoint

AccessPoint


IEEE 802.11 a/b/g

WLAN with Wireless Transit

10/100BT Ethernet

Wide variety of WirelessTransit technology

4


AccessPoint

AccessPoint


IEEE 802.11 a/b/g

Wireless Mesh

10/100BT Ethernet

Wireless transit withInter-AP ‘Meshing’ protocol

5

Enterprise / ISP BackboneNetwork

Enterprise / ISP / MetroDistribution Network

Prototype Network ArchitecturePrototype Network ArchitectureInternetat large

NAP-R2 NAP-R3

CAN-Alpha

CAN-Beta CAN-Gamma

AP = Wireless Access PointCAN = Community Area NetworkNAP-R = Network Access Point RouterNOSS = Network Operations & Support ServicesWG = Wireless GatewayWMN = Wireless Mesh Network

NAP-R1

OAM&PServiceAAA

ServiceDHCP

Service

SubscriberMgmt Service

PolicyService

NOSS

Firewall,NAT, etc.

BorderGateway

AP

AP

WG-2WG-1

6

Enterprise / ISP Enterprise / ISP BackboneBackboneNetworkNetwork


Nortel Wireless Mesh Nortel Wireless Mesh NetworkNetwork ArchitectureArchitectureInternetat large

CAN-Alpha

CAN-Beta CAN-Gamma

NAP-R1

NAP-R3NAP-R2

WG-2

Firewall,NAT, etc.

BorderGateway


OAM&PServiceAAA

ServiceDHCP

Service


PolicyService

NOSS

Enterprise/ISP Backbone Network• Carry IP traffic between Wireless Gateways (WG) and other

elements of the Enterprise / ISP Network (e.g. Border Gateways (BG), NOSS servers).

7


Enterprise / ISPEnterprise / ISP / Metro/ MetroDistribution NetworkDistribution Network

Nortel Wireless Mesh Network ArchitectureNortel Wireless Mesh Network ArchitectureInternetat large

NAP-R3

CAN-Alpha

CAN-Beta CAN-Gamma

NAP-R2

Enterprise/ISP/Metro Distribution Network• Carry IP traffic between Wireless Gateways (WG) and Network

Access Point Routers (NAP-R).• May be a Layer 3 routed, or• May be a Layer 1 or Layer 2 transport domain

NAP-R1

WG-2WG-1

Firewall,NAT, etc.

BorderGateway


OAM&PServiceAAA

ServiceDHCP

Service


PolicyService

NOSS

8




NAP-R2 NAP-R3

CAN-Alpha

CAN-Beta CAN-Gamma

NAP-R1

BorderBorderGatewayGateway

Firewall,NAT, etc.

Border Gateway• incorporates all functions required to interface with the Internet-at-Large.• Advertises reachability to the Internet-at-Large for IP addresses assigned to WMN

subscribers and network entities.• May also provide connectivity for other, non-WMN Enterprise / ISP entities.• May also incorporate other inter-networking functions (e.g. NAT, firewall, redirection).• Has no knowledge of WMN-specific mobility and security functions.

WG-2WG-1


OAM&PServiceAAA

ServiceDHCP

Service


PolicyService

NOSS

9




WirelessWirelessGatewayGateway

NAP-R2 NAP-R3

CAN-Alpha

CAN-Beta CAN-Gamma

Wireless Gateway• Advertises reachability (within Enterprise / ISP Distribution Network) for one

or more IP subnets assigned to WMN subscribers and network entities.• Hides WMN-specific mobility and security functions from the rest of the

Enterprise / ISP Distribution and Backbone Networks.

NAP-R1

WG-1

Firewall,NAT, etc.

BorderGateway


OAM&PServiceAAA

ServiceDHCP

Service


PolicyService

NOSS

10


Enterprise / ISP . MetroDistribution Network


NAP-R2

CAN-Alpha

CAN-Beta CAN-Gamma

NAP-R1

OAM&PServiceAAA

ServiceDHCP

Service


PolicyService

NOSSNOSS

NAP-R3

WG-2

Firewall,NAT, etc.

BorderGateway

Network Operations and Support Services• Centralised monitoring and managing network operations.• Interface to distributed elements of the WMN network through standard protocols I.e.

DHCP, SNMP, RADIUS.


11

Prototype Wireless Access Point Prototype Wireless Access Point Radio Networking TechnologyRadio Networking Technology

MN MNMN

Transit Link (TL) @ 5 GHz• Elevated dual-polar antennas

with switched-beams .• 802.11a

Existing utility pole or wall offering elevated mounting position

Access and Transit links separated in space and frequency

Access Link (AL) @ 2.4 GHz• Elevated, dual-polar, diversity

switched antennas.• 802.11b/g

Mobile nodes using standard 802.11b/g NIC and software

Prototype Wireless Access Point (AP)

MN

12

N

S

Access Link coverage is typically less than reach

of Transit Link

Beam patterns overlap to avoid need for alignment

during installation

Prototype Wireless Access PointPrototype Wireless Access PointSwitched Beam Antenna for Transit LinksSwitched Beam Antenna for Transit Links

• Antenna structure integrated into AP

– A beam is selected for communicating with each of the neighbouring APs.

• Multiple degrees of freedom for each transit link

Ø BeamØ FrequencyØ PolarisationØ Burst time

NAP

Primary direction of

selected beam

Having multiple beams alleviates deployment

difficulties, even if only a few are ever used in practice

N

S

13

Prototype Wireless Access Point Prototype Wireless Access Point Transit Link Radio SystemTransit Link Radio System

• 802.11a standard physical layer

• ‘Meshing’ protocol above the MAC layer for transit link discovery, establishment, monitoring, maintenance, re-establishment

• Automatic assignment of channels according to local conditions and AP neighbourhood

• Consideration - Availability of 5GHz band in different countries

14

Prototype Access PointPrototype Access Point

15

Wireless Mesh ApplicationsWireless Mesh Applications

• Ad Hoc Networks

• Access Networks with minimal cable infrastrcuture

• Out door and in door campus

• Public Metro Wireless Networks

Thank YouThank You

wireless mesh network technical overview

Documents