How Home Hotspots Could Hit Hurdles
There's more to consider about cable's home-based WiFi hotspots than most people know.
Under the industry's Community WiFi initiative, cable companies, and particularly Comcast Corp. (Nasdaq: CMCSA, CMCSK) in the US, are spreading the WiFi wealth by activating wireless home routers for use as public, shared hotspots. Guest users are separated from home users through the use of dual service set identifiers (SSIDs), and -- from both a security perspective and a bandwidth monitoring perspective -- traffic is managed and accounted for very differently. (See Comcast's Home Hotspots Heat Up.)
However, Community WiFi is still a shared-spectrum experience. This means that use of the public SSID on a home router can still cause performance problems for the private hotspot subscriber.
At the DOCSIS 3.1 and Wireless Symposium in Denver last month, CableLabs Architect Vivek Ganti explained it this way: Imagine a public user 50 feet away from an access point wants to upload a photo to Facebook while the owner of the home hotspot is trying to send email only 10 feet away. Because WiFi is egalitarian, if the guest user grabs the upstream channel first, it creates congestion on the network, making it difficult for the home subscriber to send email.
Charlie Douglas, executive director of corporate communications at Comcast, confirmed that home hotspots could experience network congestion from guest users simply because of the way that WiFi works. "If you were at a baseball stadium, and it was empty, and the WiFi was on, and you were there by yourself, you would have an amazing experience," Douglas elaborated. But, he continued, if the stadium filled up, your online experience would slow down.
Douglas, however, was quick to point out that Comcast hasn't received reports of performance problems on home hotspots because of added traffic from guest users. "It's not something we're seeing," he said. He also thinks problems are unlikely in the future because of WiFi's limited range. A guest user would need to park and stay parked near someone's home hotspot in order to take advantage of it.
CableLabs also confirmed in an official statement that "Across our cable operator membership, we are not seeing subscriber complaints of home hotspot performance due to visitors." A spokesperson added that it's possible to link a WiFi SSID to a DOCSIS service flow, which would also allow a service provider to lower overall traffic priority or throughput levels for the public SSID and thereby raise them for the private one. That could mitigate the risk of service degradation for home users, but it still wouldn't solve the problem entirely at the end of the consumer connection where WiFi limitations remain.
Despite such assurances, it's difficult to predict what will happen as community hotspot networks continue to grow and more consumers become aware of new opportunities to connect to the Internet. For homes in densely populated areas, or in locations that are next to gathering places like a neighborhood park or swimming pool, network congestion could become a problem. Previously, the only way for a guest user to access a subscriber's WiFi at home was if the owner kept that WiFi connection open and unencrypted. Now, from a bandwidth perspective -- although not a security one -- a subscriber's wireless connection is open by default in many home hotspot deployments.
Further, some subscribers on a Comcast online user forum, and on a forum hosted by DSLReports, have reported numerous difficulties when trying to turn off the home hotspot feature. Comcast's Douglas counters that argument by pointing out that fewer than 1% of subscribers have asked the company to switch off the hotspot function, but that may be as much a result of low awareness as of users not wanting the feature activated.
Meanwhile, several operators and industry organizations are working to improve quality-of-service (QoS) controls over the WiFi experience. Institute of Electrical and Electronics Engineers Inc. (IEEE) , Wi-Fi Alliance and Wireless Broadband Alliance are all collaborating on technologies that would enable application-based traffic prioritization, as well as on a specification that would define a mechanism for determining when an access point is overloaded so that it can reject any additional sign-on requests. Those innovations and others are part of a movement to develop carrier-grade WiFi -- WiFi service that operates more like cellular broadband. However, true carrier-grade WiFi is still a couple of years off. (See Carrier-Grade WiFi Still 2 Years Away – CableLabs.)
In the meantime, cable's ambitious Community WiFi initiative may be in for some growing pains… particularly if cable WiFi usage takes off the way operators want it to. "WiFi is really our mobile network of choice," Comcast vice president Tom Nagel said earlier this year. That may be true, but it still has some maturing to do.
— Mari Silbey, special to Light Reading