US-Korea Joint Workshop onDigital LibrariesSDSC - August 10-11, 2000

Edward A. Fox and Cortney Martin

Virginia Tech, Blacksburg, VA, USA

Broadband Wireless Networking in Rural VirginiaCase study: Blacksburg

#2

Applications such as digital libraries, distance learning, telemedicine, video streaming, videoconferencing, and the e-economy are dependent on next generation broadband networks. But these applications hit a bottleneck at most offices and homes.

High Capacity Backbone Network

Modem, DSL, Cable Modem

The Problem

Largely copper and coax

#3

Connectivity Options

• Dial-up Modems

• xDSL - limited availability, constraints on distance from CO.

• Cable Modems- shared medium limits avail. bandwidth, not available to most businesses.

• Satellite – one way, uses telephone return; not good for serving information.

• Leased lines

• Direct Fiber – limited availability

Bandwidth

Affordability

#4

One Solution is Broadband Wireless, or LMDS• Local Multipoint Distribution Service

– A “Last Mile” communication solution

– 1150 MHz of licensed microwave frequency in 28-31 GHz range

– A broadband wireless alternative to fiber, copper or coax

– Will remove the bottlenecks between advanced communication networks and the home and office

– More than twice the bandwidth of the combined total of radio, broadcast television, and cell telephone

– Throughput of 10 Gbps (10,000 Mbps)

Virginia Tech Won Four A Block Licenses in the 17th FCC Spectrum Auction

BTA pop sq miles

Bristol 698,000 6,207Danville 171,000 2,280Martinsville 92,000 881Roanoke 644,000 7,139

total 1,605,000 16,507

BTA pop sq miles

Bristol 698,000 6,207Danville 171,000 2,280Martinsville 92,000 881Roanoke 644,000 7,139

total 1,605,000 16,507

40% of the area of Virginia

#6

LMDS offers a LOT of bandwidth(comparison to previous auctions)

0 200 400 600 800 1000 1200MHz

Interactive & Video Data

Wireless Communications Service

PCS D-F Block

Digital Audio Radio Service

Cellular Unserved

PCS A-C Block

DBS

MMDS

LMDS

LMDS is:- 1300 MHz in two “Blocks” ( 28-31 GHz)- Over 2X bandwidth of AM/FM radio, VHF/UHF television, and Cellular telephone combined.- More than sum of previous 16 auctions

LMDS is just another access medium and can be used for voice data or video

A network can be made up of any combination

of point-to-point wireless, point-to-

multipoint, and wireline solutions

Images from www.wavtrace.com

#8

Advantages of LMDS

• Fast to deploy, no digging roads

• Solution to lack of fiber in some rural areas

• Build-out on demand, scalable

• Multi-Gigabit capacity

• Can provide integrated services: voice/data/video

Challenges• Requires “line of sight” between Tx and Rx

• Signal attenuation by rain and moisture in vegetation

• Shorter range requires more hub sites for coverage

#9

Multi-disciplinary Team is Working to Solve the Problems

• Information Systems

– Communications Network Services

– Digital Library Research Laboratory

• Academic Departments & Research Centers

– Center for Wireless Telecommunications

– Space and Wireless Business Center (SAWBUC)

• Virginia Tech Foundation

• Area Communities

Operational Deployments, Community Outreach

Engineering and Business Research

#10

Virginia Tech and Wavtrace Deployed an LMDS Testbed in Blacksburg, VA

• First deployed in May, 1999 - First TDD system, first rural deployment

• Wavtrace Point-to-Multipoint wireless SONET supports N x T1 at remote sites

• Typical services include Ethernet/IP and T1 channels for Internet/Intranet access; analog voice lines; VoIP; streaming video; H.323/MPEG-2 videoconferencing

• Wavtrace next generation system uses wireless ATM to support up to 180 Mbps per carrier

Blacksburg LMDS Deployment March 2000(Hub, 3 beams, 8 remotes; serving offices, apartments, ISPs)

Area: 19 sq milesPop: 36,000

#12

Viewshed From LMDS Hub

#13

LMDS Hub Site at Slusher Hall

Radio Hut

Wavtrace Tower 1 Wavtrace Tower 2

#14

Hub Indoor Equipment at Slusher Radio Hut

OC3 link to MSAP

Net Mgmt Ports

#15

Slusher Tower

Remote outdoor equipment can be mounted in a variety of ways

#16

Apartment Owners Want Obscure Antennas

Wavtrace Remote TRA

#17

Weather data is collected at several sites

• Signal attenuation due to rainfall continues is of interest to the industry

• Rain cells are typically small

• Station tracks:– Outdoor temperature

– Indoor temperature

– Wind speed and direction

– Rainfall http://remote1.lmds.vt.edu/weather.htm

#18

Temporary Indoor Equipment ConfigurationAdtran T1 CSU/DSU/Voice Mux

Baytech Remote Controller

Cisco 2621 Router

3COM Ethernet Hub for Mgmt

Wavtrace Indoor Unit

#19

Experience with LMDS

• Quick to deploy (enables service provider to capture customers before a competitor does)

• Build-out, or relocate, as needed

• Useful for sites not readily accessible to other broadband services

• Signal loss due to rain must be compensated for

• Operation, Administration, Maintenance, and Provisioning is similar to other telecomm. equip.

#20

Ways to Profitability?

• Provide good performance and reliability• Create an MSAP for local high speed peering,

collocation, and content services• Bundle and/or integrate voice, data, and video

services–partner if needed• Make use of fiber, twisted-pair, coax, and other

media, in addition to wireless, where effective

LMDS Connects to Blacksburg MSAP (Multimedia Service Access Point)

LocalBusinesses

LocalGovernment

LocalSchools

LocalBusinesses

LocalISP

WirelessLMDS

College-Univ.

IPRouting Directory

Security

Content

ManagementMSAP

Cache

LocalISP

InternetNetwork VA /Internet

Local NAP

Fiber

Community• Facility for local peering and

collocation of broadband network and appl. services

• Reduces cost for service providers by reducing need for higher tier Internet capacity

• Improves network performance by removing Internet bottlenecks

• Facilitates broadband applications (e.g., VoIP, music, video on demand, home office, distance learning)

• Makes customers happy!!!

Eventually LMDS could be used in combination with other wireless and wireline technologies to reach individual homes

#23

There is a great deal of interest in LMDS in rural SW Virginia and planning for deployments is underway by CNS and CWT

Smyth County

Floyd County

Cortney MartinCommunications Network Services

For more information:www.lmds.vt.edu

lmds@vt.edu