doc.: ieee 802.11-04-1478-00-0wng submission nov 2004 ted rappaport, wncg, univ of texasslide 1...

Nov 2004

Ted Rappaport, WNCG, Univ of Texas

Slide 1

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Site-Specific Knowledge for

Next Generation Wireless Networks

Prof. Ted RappaportWireless Networking and Communications Group

Department of Electrical and Computer EngineeringThe University of Texas at Austin

November 17, 2004

www.wncg.org

Nov 2004


Slide 2

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Some Wireless Next Generation Activities • WiFi and 3G combination chipsets

• UWB/Home Media Gateway

• MiMo and OFMD-based modulation

• Advanced Security

• Cross Layer, Universal MAC

• Integrated Multiband/colocated antennas

• Mesh Networks/Site-specific Radio Management

Nov 2004


Slide 3

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Site Specific knowledge is needed in Next Generation Networks

• We can substantially increase battery life, network performance, enhance coexistence, reduce support calls, and deploy no-fault wireless using “site specific” knowledge

• PHY/MAC/Radio Resources of today will move to baseband processing and digital “environmental map” in each client

• Power vs. processing tradeoffs: RF power consumption and Network Inefficiencies (today) versus baseband processing and client’s environmental awareness (next gen)

• Myriad new services, capabilities become viable

Nov 2004


Slide 4

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Computing and device trends• Vector graphics, 3-D processing capability evolving

naturally as part of microprocessor

• Multiple radios, frequency bands, applications, to become part of PCs, phones, home media, enterprise network products

• Memory costs and cost per MIPS decreasing exponentially, at much faster rate than battery and RF antenna/propagation breakthroughs

• History of wireless has not exploited environmental/spatial knowledge in the network, yet propagation depends solely on this!

Nov 2004


Slide 5

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Wireless Technology and Semiconductor ROADMAP

Year Technology Gate Width (nm) [2]

Vdd Treshold (V) [1]

Saturation Current (uA/[Vum]) [1]

1990 900 MHz Cellular

800 5 150

1996 1800 MHz 2G Cellular

275 2.5 – 1.8 200

2001 2.4 GHz 802.11b

130 2.5 – 1.8 300

2003 5.8 GHz 802.11a

100 1.8 – 1.5 375

2004 UWB 90 1.8 – 1.5 400 2006 10 GHz

anticipated BWA

60 1.5 – 1.2 500

2010 30 1.2 - 0.9 650

Source:1. Hotta, Imasao, Shoji Shukuri, and Koichi Nagasawa. “Trends of Semiconductor Techonology for

Total System Solutions.” http://www.hitachi.com/rev/1999/revapr99/r2_101.pdf.2. http://phys.cts.nthu.edu.tw/workshop/tp5/20031204/T.%20F.%20Lei.pdf

Nov 2004


Slide 6

doc.: IEEE 802.11-04-1478-00-0wng

Submission

ITRS Technology Nodes and Chip Capabilities

2001 2005 2010 2016

Microprocessor Speeds (MHz)

1,684 5,173 11,511 28,751

Gate Length (nm) 65 32 18 9

DRAM Cost/bit (micro-cents)

7.7 1.9 .34 .042

DRAM memory size 512M 2G 8G 64G

Source: http://www.sia-online.org/downloads/itrs_2001.pdf

Nov 2004


Slide 7

doc.: IEEE 802.11-04-1478-00-0wng

Submission

A paradigm shift – learning from Qualcomm

• Qualcomm changed the wireless world:• Narrowband radios became wideband radios• Tight RF filtering became sloppy RF filtering• Channel selection became a baseband processing

chore, not an RF/IF chore –plays to Moore’s law• Moving the processing to baseband enhanced the

network coordination/interoperability and led to flexible upgrade path to data/3G

• Intellectual property enforcement

Nov 2004


Slide 8

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Challenges Qualcomm faced

• Convincing carriers that CDMA improved spectral efficiency, made network deployment easier, increased users and revenue per MHz

• Convincing carriers to relearn how to design and install base stations (no frequency planning, but code offset planning and soft handoff thresholds)

• End User has to wait 8 seconds for Qualcomm phone to detect pilot and synch channels, 50 ms speech coder delay, and immediate “hard dropped” calls

Nov 2004


Slide 9

doc.: IEEE 802.11-04-1478-00-0wng

Submission

A paradigm shift Site-Specific propagation knowledge

• Site-specific knowledge will change the wireless world:

• MAC/PHY/QoS/applications will match the propagation environment, instead of being rigid/iteratively implemented

• Channel selection, power level settings, and network provisioning becomes a baseband processing chore, not an RF/IF chore involving radio usage.

• Moving the processing to baseband enhances network coordination/interoperability and leads to flexible upgrades,interference mitigation, position location, 4G

• Intellectual property enforcement (Standards – sharing)

Nov 2004


Slide 10

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Challenges for Site-specific adoption

• Convincing chip makers that networks perform better with lower battery drain, plays to Moore’s law if “environmental map” is digitized and exploited

• Convincing OEM/ODM/ box makers that site-specific network planning and management reduces support calls, reduces user problems, and enhances network performance and features

• Some site-specific data must be obtained at some point

Nov 2004


Slide 11

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Today: Network Deployment• The need for site-specific prediction models

– Many consumers and IT professionals deploy WLAN by trial and error due to limited awareness of antenna and propagation issues. Poor experiences…..

– Models exist for signal-strength predictions, throughput coverage, viable CAD software.

– Internet users and vendors are interested in application throughput for many different user profiles.

– To manage interference, improve QoS, and end-user quality, site-specific CAD design/deployment now being used – large deployments starting to rely on CAD

– Eventually, this must become a commodity and brought into networks for management of devices

Nov 2004


Slide 12

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Network Coverage Software Used by IT Admin./ Network Integrators

Nov 2004


Slide 13

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Site-specific Prediction Models

• Predictions of signal strengths in buildings [Seidel, Rappaport,1994], [Durgin et al,1998];

• Throughput prediction models [He01], [Ra00]

4log20)()( 10dPLGGPdP RTTR

b

Xba

XadndPL 10

log10

Nov 2004


Slide 14

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Extensive measurements to validate site-specific throughput

• Sites: Three restaurants (Schlotzsky’s deli)• Apparatus: laptops, IEEE-802.11b

wireless network interface cards (NICs): Cisco and ORiNOCO

• Throughput Measuring software: LANFielder (Wireless Valley Inc.), Iperf, Wget (FTP)

• Measurements conducted outside of normal business hours

• Measurement Scenarios: 1. single user; 2. multiple users

Nov 2004


Slide 15

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Single-user Measurement Platform

Nov 2004


Slide 16

doc.: IEEE 802.11-04-1478-00-0wng

Submission

The Guadalupe Restaurant

Partition description Color Attenuation (dB)

Glass doors and windows

Red 5.26

Concrete block walls Dark gray 6.83

Wooden partitions Light blue 4.70

Short counters Light gray 0.50

Nov 2004


Slide 17

doc.: IEEE 802.11-04-1478-00-0wng

Submission

The Northcross RestaurantPartition description Color Attenua

tion (dB)

Glass doors and windows Red 5.65

Concrete block walls Dark gray

8.39

Wooden partitions Light blue

0.59

Short counters Light gray

1.84

Metallic racks Yellow 7.47

Tree Green 0.10

Nov 2004


Slide 18

doc.: IEEE 802.11-04-1478-00-0wng

Submission

The Parmer Restaurant

Partition description Color Attenuation (dB)

Glass doors and windows

Red 2.00

Concrete block walls Blue 5.10

Wooden partitions Yellow 3.48

Short counters Light gray 0.50

Stony pillars Purple 1.50

Thin pillars Green 3.00

Nov 2004


Slide 19

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Multi-user Measurement Platform

Nov 2004


Slide 20

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Multi-user Measurement Applications and Tools

Client Server

Computer Dell C640 & HP Omnibook Compaq N600c

OS Windows XP Windows XP

NIC Cisco & ORiNOCO N/A

FTP Wget IIS

LANFielder LANFielder Client LANFielder Server

Iperf Iperf Client Iperf Server

SNR LANFielder & netstumbler N/A

Nov 2004


Slide 21

doc.: IEEE 802.11-04-1478-00-0wng

Submission

11 locations (Guadalupe)

Nov 2004


Slide 22

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Two Throughput Models that relate site-specific SNR to Throughput

• The piecewise model

• The exponential model

)(,

)(,

0

max

dBSNRSNRifSNRSNRA

dBSNRSNRifTT

cp

c

01maxSNRSNRAeeTT

)()( 0max dBSNRA

TdBSNR

pc

Nov 2004


Slide 23

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Cisco card data

Guadalupe

Northcross

Parmer

All three restaurants

Nov 2004


Slide 24

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Cisco card data (spatial average)

Guadalupe

Northcross

Parmer

All three restaurants

Nov 2004


Slide 25

doc.: IEEE 802.11-04-1478-00-0wng

Submission

For General In-Building Environments

• Spatial Average

• All Three Restaurants

• Cisco card

• Exponential model

• Scales to 3 different apps.

• Also see 802.11-04-1473-00-000t

Tmax

(Mbps)

Ae

(dB-1)

SNR0

(dB)

μ (Mbps) σ

(Mbps)

R(%)

Iperf 5.26 0.069 5.39 0 0.88 76.4

Wget 4.47 0.0747 11.0 0 0.615 90.9

LANFielder 1.76 0.113 8.25 0 0.295 81.1

Nov 2004


Slide 26

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Blind Throughput Predictions for a New Environment using Site Specific map

• Predicted RSSI in dBm– Use [Se94,Du98] models, auto-tuning implemented in site-

specific prediction tool LANPlanner by Wireless Valley

• The ambient noise level in dBm– Perform a quick calibration test in the new environment

(typical value: -90 dBm)

• Mapping SNR to throughput for different apps– Determine Tmax by back-to-back calibration tests; use Ae

and SNR0 of foregoing results

Nov 2004


Slide 27

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Performing Tests in WNCG

• Noise is -90 dBm• Tmax for LANFielder was

calibrated as 2.403 Mbps• Reading the table, Ae is

0.113 dB-1, and SNR0 is 8.25 dB

25.8113.01403.2 SNReT

Nov 2004


Slide 28

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Site-specific RF Network Management

DESIGNED DEPLOYED

SSIDCOVERAGE

RF REMEDIATION / RECONFIGURATION w/SITE SPECIFIC

Nov 2004


Slide 29

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Deployed Network Coverage

Cube-farm has no coverage in the deployed network due to human deployment error or “bad” equipment

Nov 2004


Slide 30

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Deployed Network Coverage- Autonomous Network Management using Site-specific knowledge

AP01 is automatically reconfigured using digitized map at switch; cube-farm now has coverage in the deployed network

Nov 2004


Slide 31

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Home and Enterprise Network Management System using Site-specific knowledge

• How does it work?– User spends approximately 30 - 60 seconds inputting basic site-specific

information into a GUI

– Software uses site-specific algorithms on a digital map to determine coverage areas and optimal equipment positions/configurations within the environment; digitizes finalized infrastructure map and pushes to clients

– Devices share site-specific knowledge and measured responses through the network to monitor, control, and diagnose changing RF conditions.

– Unless desired, the end user never needs to interact with the software beyond the initial network setup stages and added infrastructure – everything else is automated behind the scenes (power levels, handoff, auto-reconfig. with new nodes).

– Hidden node problem, next door neighbor is diagnosed and controlled much more reliably using site-specific knowledge

Nov 2004


Slide 32

doc.: IEEE 802.11-04-1478-00-0wng

Submission

– Embedded software on a centralized network appliance (e.g., media gateway, hub, switch, etc.) and/or on APs or clients. Leverage site-specific information stored locally on the device to make informed decisions regarding network configurations. Site specific knowledge shared with clients.

• How does it work?– Site-specific information regarding the environment and network

infrastructure is downloaded to the embedded software• Embedded software may be pre-loaded on the device or downloaded from the

Home NMS

– The embedded software monitors network and radio activity it sees in the environment

– As events occur that negatively impact network performance, the embedded software can independently analyze the event in the context of the overall network and can respond quickly with device configuration changes that are in the best interests of the overall network

Alternate Embodiments: Embedded Network– Centralized Hub, AP, Clients

Nov 2004


Slide 33

doc.: IEEE 802.11-04-1478-00-0wng

Submission

• Embedded software runs on clients either as services in the operating system, as part of a device driver, or directly integrated onto the hardware in some fashion

• Why do we need it?– This technology places intelligence in the hands of the client devices, with

greatest power concern and in closest contact to end-users– Site-specific knowledge, combined with Moore’s law in processing power,

allows mobile devices to know where, when, and how to properly manage its power, and applicability, while improving overall network performance.

– Memory and CPU requirements scale to allow this to be viable in next one to three years

– Ties in with intelligent infrastructure, security, new services– Site-specific knowledge of the client offers ultimate intelligence for

communication. Why God gave us eyes, why we like maps in new cars

Embodiment of Embedded Network Software in Clients

Nov 2004


Slide 34

doc.: IEEE 802.11-04-1478-00-0wng

Submission

Client #1:Ch 1, -59 dBm41 dB SIR24 Mbps

AP1:Ch. 61 mW802.11g

AP2:Ch. 1, 30 mW802.11g

Association

TV:Ch 6-45 dBm55 dB SIR54 Mbps

.AP1 lowers its power levels to a minimum in order to avoid serving distant clients who can be served by AP2. Client PDA stays with AP2 and has good service. TV on AP1 retains good service.

QOS in a Hybrid Environment

Nov 2004


Slide 35

doc.: IEEE 802.11-04-1478-00-0wng

Submission

AP1:Ch. 130 mW802.11g AP2:

Ch. 130 mW802.11g

Client #1:Ch 1, -42 dBm28 dB SIR1 Mbps

TV:Ch 6, -35 dBm36 dB SIR11 Mbps

Without site-specific NMS, client associates with AP1 because AP1 offers higher power levels, but interferes with TV on same channel, reduces bandwidth of TV streaming video, and experiences its own reduced bandwidth.

QOS in a Hybrid Environment

Association

Nov 2004


Slide 36

doc.: IEEE 802.11-04-1478-00-0wng

Submission

The Site-Specific Revolution….Coming to Next Generation Networks

• Theoretical formulations for quantifiable data, metrics, and tradeoffs for semiconductor baseband, RF, software, site-specific traffic, and power overhead are needed, but are emerging.

• Computing power is evolving to allow “electronic maps” to be exploited in devices for new wireless devices

• This is an entirely new and unexploited dimension to MAC and PHY – and is cross-layer processing unlike previous solutions in the wireless world

• Broad scale market adoption is likely, and IEEE should begin studying and standardizing this concept

• Why did God give us eyes, and why do we like cars with navigation systems in them – they make us more efficient

Nov 2004


Slide 37

doc.: IEEE 802.11-04-1478-00-0wng

Submission

References• [Ch04] Jeremy Chen, “Site Specific Network Throughput modeling,” M.S.

Thesis, Summer 2004, WNCG, University of Texas at Austin • [Na04] Chen Na, Jeremy Chen, T.S. Rappaport, “Public WLAN Traffic

statistics and throughput prediction,” Electronics Letters, Sept. 13, 2004• [He01] B. E. Henty, T. S. Rappaport, “Throughput Measurements and

Empirical Prediction Models for IEEE 802.11b Wireless LAN (WLAN) Installations”, ECE Dept., Virginia Tech technical report, MPRG 01-08, 2001

• [Ra00] T. S. Rappaport, B. Henty, and R. Skidmore, “System and method for design, tracking measurement, prediction and optimization of data communication networks,” pending U.S. and International Patents.

• [Du98] G. Durgin, T. S. Rappaport, and H. Xu, “Measurements and models for radio path loss and penetration loss in and around homes and trees at 5.85 Ghz,” IEEE Transactions on Communications, vol. 46, no. 11, pp. 1484–1496, November 1998.

• [Se94] S. Y. Seidel and T. S. Rappaport, “Site-specific propagation prediction for wireless in-building personal communication system design,” IEEE Transactions on Vehicular Technology, vol. 43, no. 4, pp. 879–891, 1994.

Nov 2004


Slide 38

doc.: IEEE 802.11-04-1478-00-0wng

Submission

References (II)• [He03] M. Heusse et al. “Performance Anomaly of

802.11b”, INFOCOM 2003• [Bi00] G. Bianchi, “Performance Analysis of the IEEE

802.11 Distributed Coordinated Function,” IEEE JSAC, vol. 18, pp. 535-547, Mar. 2000

• [Ch03] P. Chatzimisios et al, “Influence of channel BER on IEEE 802.11 DCF,” Electronics Letters, vol. 39, no. 23, pp. 1687–1689, November 2003.

• [Ga03] S. Garg et al, “An experimental study of throughput for UDP and VoIP traffic in IEEE 802.11b networks,” IEEE WCNC, 2003

• [Va02] A. Vasan et al, “An empirical characterization of instantaneous throughput in 802.11b WLANs,” U of Maryland tech report

doc.: ieee 802.11-04-1478-00-0wng submission nov 2004 ted rappaport, wncg, univ of texasslide 1...

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