| Matthew Gast | |
| Joint Techs February 2005 | |
| Salt Lake City, Utah |
| Flexibility | ||
| Ease of deployment of new users | ||
| Adaption to fluid user populations | ||
| Mobility | ||
| Not security or ease of use, though… | ||
| Regulatory constraints | ||
| No irradiating neighbors, even if you don’t like them | ||
| Shannon limit - maximum data rate | ||
| Forward error correction | ||
| Some bits may be corrupted, but not all | ||
| Corruption may be different for different users | ||
| Spread spectrum | ||
| Squish signal across a wide band | ||
| “Wireless wires” | ||
| Profiles adapt technology to different uses | ||
| Headset, serial port | ||
| Common uses | ||
| Keyboards, mice, etc. | ||
| Connecting GPRS uplinks and headsets | ||
| Slow (1-2 Mbps) to save power | ||
| Frequency hopping to save power | ||
| Higher-speed networks | ||
| GSM: GPRS, EDGE, 3G | ||
| CDMA: EV-DO | ||
| Not very fast | ||
| My experience is that GPRS peaks at 3 K/sec | ||
| Generally charged by the bit | ||
| When will they learn? | ||
| But what else can you do at 70 mph? | ||
| Advanced Television Systems Committee | ||
| Better known as digital TV | ||
| For TV, an MPEG2 stream | ||
| ~19.2 Mbps over TV coverage area | ||
| See coverage area on FCC at http://www.fcc.gov/mb/video/tvq.html | ||
| HD requires full bandwidth; SD does not | ||
| Spare capacity can be used for “datacasting” | ||
| “Wireless Ethernet” | ||
| LAN replacement | ||
| But not really LAN speed until recently | ||
| Security is the big attention grabber | ||
| Sit still for the talk after mine... | ||
| High density & high capacity networks | ||
| 802.11a is very helpful here | ||
| Better security with equal usability to wired backbone | ||
| Admission control | ||
| Keep your infestations out of my network | ||
| Differentiated access and policy implementation | ||
802.11 Implementation Challenges
| You have three channels in 802.11b/g | ||
| Limited capacity and backwards compatibility | ||
| 802.11n | ||
| “Pre-n” products may not be upgradable to final standard | ||
| Security standards are still emerging | ||
| Macs don’t work in WPA mixed mode | ||
| RF “etiquette” | ||
| Local authorities can’t pre-empt FCC Part 15 | ||
| 802.1AE – MAC Security | |
| 802.1af – MAC Key Security | |
| 802.21 – Inter-IEEE 802 handoff |
| msg@trpz.com |