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May 11, 2000 Chuck Bartel
Carnegie Mellon Background
Private research university (R1)
50+ buildings on 100+ acre campus
Half of buildings are on contiguous main campus
May 11, 2000 Chuck Bartel
Background -- 1994
Dozens of Mobile, Wearable, and Wireless Computing ProjectsMultidisciplinary Collaboration Spanning Several Campus BuildingsMore than $20M in Research FundingNo Comprehensive Network-- Each Research Project Left to Fend for Itself
May 11, 2000 Chuck Bartel
Vision -- 1994
Establish Common Research NetworkNSF Grant - $550,000 over 2 yearsBuild an Experimental, High-Speed, Wireless Network Support research projects in wireless
communication and mobile computing.
May 11, 2000 Chuck Bartel
Implementation -- 1995-1998
No Standard Existed for Wireless LANs Evaluation + Selection: ATT/Lucent 915Mhz
Deployed network in 5 campus buildingsEnable use by approximately 150 usersResearch Network = Limited Support
May 11, 2000 Chuck Bartel
Background -- 1998
Successful Wireless Research Network Growing use of LaptopsNeed for Wireless Production NetworkWireless LAN Standard 802.11 Adopted by IEEE Lucent Grant to Support Campus-Wide Deployment (400 Access Points/cards)
May 11, 2000 Chuck Bartel
Implementation -- 1998-2000
Deploy Network Campuswide 30+ Buildings (2.8M sq ft) + Outdoor
Areas
Use by Virtually Anyone on CampusProvide Support Equivalent to Wired NetworkLucent’s WaveLAN Product -2.4GHz, IEEE 802.11 Compliant
May 11, 2000 Chuck Bartel
Access Point Access Point - network - network device that links device that links wireless stations to the wireless stations to the wired network -- wired network -- $900/unit$900/unit
Wireless NIC cardsWireless NIC cards- EISA - EISA bus or PC card -radio bus or PC card -radio transceivers for the end transceivers for the end users -- users -- $795/card$795/card
$595/card$595/card $275/card$275/card $125/card$125/card
Key Components- Wireless LAN
May 11, 2000 Chuck Bartel
For every Access Point in a building, we need: For every Access Point in a building, we need: •110 vac plug 110 vac plug •Data cable capable of supporting a 10BaseT Data cable capable of supporting a 10BaseT connectionconnection
Since most of the Access Points end up above Since most of the Access Points end up above ceilings or other out of the way places, new ceilings or other out of the way places, new dedicated cables needed to be installed.dedicated cables needed to be installed.
Avg. cost per installed Avg. cost per installed AP $1.9K (Cost of AP- $.9K)AP $1.9K (Cost of AP- $.9K)
Wireless doesn’t necessarily mean Without WiresWireless doesn’t necessarily mean Without Wires
May 11, 2000 Chuck Bartel
Design factors to consider
Interference
Mobility – Roaming
Coverage vs Capacity
May 11, 2000 Chuck Bartel
Examples of potential interference sources in the
2.4GHz ISM band (IEEE 802.11) Microwave ovens 2.4GHz Cordless phones Bluetooth Other 802.11 LAN devices Other 2.4GHz LAN devicesHow do you regulate these on your campus?
Can you? Should you?
InterferenceInterference
May 11, 2000 Chuck Bartel
Other complicating factors
Mobility complicates wireless designs. Wireless design is as much Art as
Science. The wireless industry is evolving their
products to support campus environments (but they are still behind the wired side of networking).
May 11, 2000 Chuck Bartel
Keys to Design Success (for CMU)
We developed new approaches to building-wide wireless design with the vendor.Colorized coverage mapsDesign review meetingsDesigned for coverage (not for capacity)
Based on our experiences, the vendor improved their design tools.
May 11, 2000 Chuck Bartel
Design Futures
The “Walkabout” WLAN Design Tool
Alex HillsCarnegie Mellon University
May 11, 2000 Chuck Bartel
CMU’s Manual Design ProcessEnhances WLAN Performance
Complete coverage no gaps
Minimize co-channel overlap capacity
Lucent design manual based on process developed at CMU
May 11, 2000 Chuck Bartel
What Is Needed To Improve Design Process
A design process that is: Fast Easy to use Correct!
The “Walkabout” tool: Is much faster than manual process Requires minimal training Requires no building drawings Uses inexpensive hardware
May 11, 2000 Chuck Bartel
Walkabout Development Phases
Phase I Creates coverage map Assigns frequencies to APs
Phase II Predicts coverage map (“what if”)
after APs moved to new locations
Phase III Recommends “first cut” design
May 11, 2000 Chuck Bartel
Walkabout Phase I Tool
Temporarily position APsWalk around target space single floor building multi-floor building outdoor space
Results: Coverage map Frequency assignment
May 11, 2000 Chuck Bartel
For more info contact:
Alex HillsCarnegie Mellon University
(412) [email protected]
May 11, 2000 Chuck Bartel
Wireless Andrew Infrastructure
Standards-Based Wireless LAN in all Academic and Administrative BuildingsComprehensive Coverage with Roaming Enabled (Mobility is Seamless)Wireless LAN is Connected to the Campus Backbone and InternetSupporting 600-1000 UsersAdd’l Info available at URL:
http://www.cmu.edu/computing/wireless
May 11, 2000 Chuck Bartel
Where are we now?
We cover 14+ buildings (to date)- 240 APsWe cover 14+ buildings (to date)- 240 APs We cover over 2 M sq. ft. of office/lab/classroom We cover over 2 M sq. ft. of office/lab/classroom
spacespace We cover roughly 60% of the academic campus.We cover roughly 60% of the academic campus. We have 800+ usersWe have 800+ users
We will be adding another 16 bldgs. ( 800K sq. ft.) by We will be adding another 16 bldgs. ( 800K sq. ft.) by 6/30/2000. –Approx. 84 APs6/30/2000. –Approx. 84 APs
May 11, 2000 Chuck Bartel
Academic andAdministrative
Buildings
Residence Halls, Parking, etc
Wireless Campus by June
May 11, 2000 Chuck Bartel
How Much?? $$$, coverage
Average cost of wireless: <$1K for AP, <$1K for power/data install, + wired network infrastructure costs+design labor costs.Avg pwr/data install schedule– 8 locations / wkAvg AP installs - 8 per dayAP to sq.ft. density: depends on building construction and arch concerns, ex: older construction 25 A.P.s cover 228Ksq.ft., newer construction 12 A.P.s cover 210Ksq.ft.Best coverage 17.5Ksqft/AP, Worst 3.4Ksqft/APYour mileage WILL VARY!!!
May 11, 2000 Chuck Bartel
Wireless Andrew Issues/Futures Coverage vs capacity – Why not both? “Airspace policy” and interference –
Bluetooth,… Keeping up with demand- scaling issues Security-Authentication Next Gen 802.11(a) –5Ghz Issues: Fork-lift upgrade? Ease of transition?John Schafer will cover some of these topics
May 11, 2000 Chuck Bartel
Uses of wireless infrastructure
Untethered access to campus network: Follow-on project - Handheld Andrew: enhancing usability of palm and HPCs with access to campus network – Researcher’s “Field of Dreams”
Tracy Futhey will cover some of these topics
May 11, 2000 Chuck Bartel
Wireless “Bake-off”1 1.208666374 1.279168497 1.352422779 1.358424828 1.35842482811 1.252563788 1.339435092 1.400756011 1.4115361731 1.352746176 1.4367513 1.5192119341 1.292107434 1.3673037621 1.31168499111 1.193162701 1.2752944 1.346130738 1.3519286231 1.652914473 2.127679866 2.631609064 4.1667238881 1.143277757 1.2464651311 1.178031198 1.2540179631 1.851851852 2.5925925931 1.6747663551 1.453639515 1.936200173 2.2598570191 1.688360862 1.976205925 2.762338505111 1.688367727 2.147367381 2.845476704
29 20 15 10 5 11 1.262023804 1.675139265 2.725030441 3.724414134 6.1714975851 1.381327617 1.604411831 1.942093224 1.930880759 1.358424828
1 5 10 15 20 296.171497585 3.724414134 2.725030441 1.675139265 1.262023804 11.358424828 1.930880759 1.942093224 1.604411831 1.381327617 1
1 5 10 15 20 2946,397 46,397 46,192 43,690 41,282 34,15545,990 29,873 18,558 12,336 10,034 7,452
Effect of network loading on a single host
41,282
34,155
18,558
7,452
43,690
46,19246,39746,397
10,034
29,873
45,990
12,336
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
1 5 10 15 20 29
Number of simultaneous FTP transfers
FTP
tran
sfe
r r
ate in
Bytes p
er S
econ
d
10-base-T wired
Wireless
46,397
45,990
46,39729,873
46,192
18,558
43,690
12,336
41,282
10,034
34,155
7,452
0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000
FTP transfer rate in Bytes per Second
1
5
10
15
20
29
Nu
mb
er o
f sim
ult
an
eou
s F
TP
tran
sfe
rs
Effect of network loading on a single host
Wireless
10-base-T wired