Cablevision's member-only Optimum WiFi service now offers up to 15 Mpbs down and 4 Mbps up: The network is free to Cablevision's broadband subscribers, and restricted to them, although the firm also allows some roaming from other cable providers' customers, and has free and open hotspots here and there.
The company tells me it has 10,000s of access points in place across its New York, New Jersey, and Connecticut markets, along with 7,000 hotspots in business locations that are Cablevision customers. Over 500,000 Cablevision customers have used the network so far.
Wi-Fi networks, even at 802.11g speeds, can easily handle 15 Mbps over short distances. With 802.11n, 15 Mbps should be achievable over longer ranges.