Wireless Long-Term Issue Wireless LANs Issues for Infrastructure Support Mark Poepping Carnegie Mellon Tucson CSG 2/4/2000

Issues Physical Management Other Stuff

Physical Issues Bandwidth Coverage Capacity Design Implementation Logistics

Bandwidth, Coverage Bandwidth of 2.4GHz 2Mb, 11Mb Mixed cell, mixed speed Coverage 6-20k sq ft 10k ‘typical’

Capacity Per Cell (csma/ca) 2Mb: 25 per cell; 11 Mb: ? per cell Multi-Channel Overlay or Allocation Infrastructure vs Local Cell Shape/Size Directional antenna (2-way) Perimeter threshold – not standard

Design Propagation Building Architecture/Materials Shielding (walls, cabinets, whiteboards) Waveguides (hallways) Interference Microwave oven, other 2.4 wireless Other AP’s Channel Reuse

Channel Overlap

Implementation Single AP Vendor (mgmt) Methodology Basic Layout (some tools available) Test and Measure Tweak and Retest Logistics Power and Wiring Aesthetics

Issues Physical Management Other Stuff

Management Issues Topology Roaming vs. Routing Airspace Reserved Channel?

Management Issues - 2 Security Access Network Name (open/closed) DHCP control Egress filtering WEP for small environments only Encryption - WEP is ineffective Key distribution doesn’t scale

Management Issues - 3 Configuration Management AP software Radio firmware (AP, client) Client driver Management Software

Management Issues - 4 Measurement and Troubleshooting Dynamic Environment enhances need No Enterprise tools Historical traffic analysis Proactive troubleshooting

Other Stuff Products Values/Benefits/Uses Coming Non Stuff

Products Vendors (e.g.) Lucent WaveLan Cisco Aironet Nortel BayStack 600 Apple AirPort APs ~$300 NICs ~$100 5v PcCard (no 3.3v; no CFlash) HandSpring Springboard card

Values/Benefits/Uses On-Campus Ubiquitous access (really) Research environment Devices Human Factors Management Off-Campus Home networking (w/ DSL)

Coming a - 5.2GHz band 54Mb point-to-point Layout Tools Nortel Web-based simple costing CMU tool (Alex) - coverage/capacity

Non Stuff Phone devices WAP Clippings Bluetooth

Wireless Long-Term Issue Wireless LANs Issues for Infrastructure Support Mark Poepping Carnegie Mellon Tucson CSG 2/4/2000