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- WiFi 802.11a, b, g, n (reliability, performance, security, ubiquity (starting to appear on airlines)
- 802.11n throughput increase 8 times per radio, WiFi connect rates increase nearly 6 times
- Reliability vs wired
- RF obstacles like walls, heavy channel utilization, poor RF network design, bad client drivers, difficulty of management
- WiFi relies on shared access RF medium in unlicensed spactra prone to interference (cordless phones, video controllers ...).
- Requires multiprong approach resilient architecture with no single point of failure, mesh support, power adjustments and automatic channel changing to cover gaps if AP goes offline, automatic backup cellphone link
- Mesh networks of clients discover each other, connect securely (WiFi Direct standard) in ad hoc networks. As long as carriers allow it, they will also be able to serve as hubs for small local networks, linking several devices via Wi-Fi and letting them share the phone's 3G or 4G Internet connection.
- 802.16m will be significantly faster than its predecessor. WiMAX Forum Vice President Mohammad Shakouri has said the goal is for the new WiMAX standard to deliver average downlink speeds of more than 100Mbps to users. In contrast, Sprint's initial Xohm WiMAX offering, which debuted commercially in 2008, delivered downlink speeds ranging between 3.7M to 5Mbps. But while 802.16m will give WiMAX a major speed boost, don't expect it to propagate any further than the current WiMAX technology that covers around 31 square miles per access point.
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The number of phones shipped with Wi-Fi jumped to 139.3 million in 2009, up from 92.5 million in 2008, ABI's research indicates that annual shipping number will surpass 500 million units by 2014, when 90 percent of all smartphones will have the technology. At least one phone with 11n – Samsung's Wave – has been announced. An 11n network is also more efficient, so the phone will expend less energy communicating http://www.networkworld.com/news/2010/032310-wi-fi-spreading-fast-among.html
Other
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Mobile devices
- Not considering cordless phones, CB radios, pagers
- Iridium: catastrophes (Haiti), hard to reach places: expeditions, Arctic …
- ATT Terrestar hybrid cell & satellite switches to satellite when out of range, covers US, looks like Blackberry, not cheap $799 + $5/month on top of regular voice & data. Calls are $0.65/min. See http://www.pcworld.com/article/172944/terrestar_satellite_phone_coming_to_atandt.html
- Laptops, netbooks (OLPC), smartbooks (kindle,iPADs), Cell phone and smartphones
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