Wi-Fi limitations and the high expectations of San Francisco citywide coverage

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Fabien Girardin reports on some of the problems encountered with the Wi-Fi network at his university. While this is not totally unusual, the fact that his university displays what he calls Deficient WiFi Awareness Sign is quite significant. It is much more usual to see signs that announces the availabilty of Wi-Fi rather than its non-existence or non-availability. This shows that Wi-Fi is becoming in some places a commodity that is expected to be present. While it is in theory possible to fully cover an area with Wi-Fi connectivity, there is no such thing yet as guaranteed connectivity while using a wireless medium like Wi-Fi.

Deficient WiFi Awareness Sign

One of the problems with wireless communication systems like Wi-Fi is that they are more likely to encounter problems than a wired communication system. There is, in some ways, some “mystery” left on how radio frequency signals works that we still need to figure out if you want to get the perfect connection. Wireless signals are much more likely to suffer interferences and this is especially true for Wi-Fi which operates in an unlicensed frequency range.

In addition to other devices trying to access the Wi-Fi, microwaves, cordless phones, computer accessories and even building structures can disrupt a perfectly well configured Wi-Fi connection.

While the technology is seeing constant improvement, it is still complex to plan or even monitor the behavior of a wireless connection.

One of my lab colleagues did his master’s thesis on the problem of placing the wireless access points. The tool he designed made use of a extremely complex set of equations and high number of calculations to find near optimal solutions to the placement of the access points for a 80×60 meters floor plan, while setting several constraints in his model. So knowing how complex the placement of access points would be for a “simplified” floor plan, I can understand that the same exercise for a citywide coverage is far from trivial.

As I was going through the request for proposal for San Francisco TechConnect, I found the expectations for the San Francisco Wi-Fi network far from what I expected (they are located under the Coverage section (p 9))

  • Outdoor coverage shall be provided for Basic and Premium Services for a minimum of 95% of all areas of the City. An area is considered covered under this requirement if a laptop, interface – can access the Network at the provisioned service level with no additional hardware required beyond the device’s standard wireless interface.
  • Indoor, Perimeter Room coverage for the ground and second floors of a building shall be provided for Basic and Premium Services for a minimum of 90% of all residential and commercial buildings throughout the City. A building is assumed covered under this Specification if a device located in each Perimeter Room on the ground and second floor of the building can access the Network at the provisioned service level. This coverage requirement may be met by using a Wi-Fi interface built into a user’s device, a signal amplifier, a high-gain antenna and/or a dedicated Wi-Fi bridge or other type of CPE.
  • Indoor, Perimeter Room coverage shall be provided for Basic and Premium Services above the second floor for 90% of all residential and commercial buildings throughout the City. A building is assumed covered under this Specification if all Perimeter Rooms on all floors of the building can access the Network at the provisioned service level.

The problem with these requirements, along with others in the San Francisco RFP, is that they are extremely hard if not impossible to guarantee . So, I wasn’t surprised tonight when they announced the results that Earthlink/Google the leading candidate only got a grade of around 65% for their proposal.
Earthlink/Google proposal acknowledge that they don’t fully comply with the above requirements and states in their proposal that

It is difficult in practice to achieve 90 to 100% indoor coverage with any wireless network above the second floor or for interior rooms. Cellular systems are a good example, and users have already become accustomed to moving around to find a good signal for such services. (p 63)

So while we wait for the perfect wireless system to be designed, we should keep moving around to find a good signal and plan for failure accordingly. Maybe Earthlink should start printing signs to post around town!!

Wi-Fi: Sharing, Piggybacking and the legal implications

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Lately, there has been a lot of discussion on Wi-Fi access sharing. This is not a new topic but it has probably found a new life with FON building a business model around people sharing their Wi-Fi access and FON getting major funding from both Skype and Google. I probably have to thank Martin Varsavsky for all the press and blog coverage it is generating and the material I can use in my research.Lock

Since I am still in the middle of my Wi-Fi survey (you should take it if you haven’t done so already) that focuses on these issues of sharing, usability and legal implications, I won’t comment on the topic now but just provide some pointers and “interesting” quotes. I am also preparing a case study on FON, big municipal Wi-Fi initiatives like San Francisco TechConnect and the likes.
It is amazing what people will say to defend one or the other position of this topic. Especially the analogies!

From the New York Times story titled Hey Neighbor, Stop Piggybacking on My Wireless (Mar 5th 2006)

For a while, the wireless Internet connection Christine and Randy Brodeur installed last year seemed perfect. They were able to sit in their sunny Los Angeles backyard working on their laptop computers.

But they soon began noticing that their high-speed Internet access had become as slow as rush-hour traffic on the 405 freeway.

“I didn’t know whether to blame it on the Santa Ana winds or what,” recalled Mrs. Brodeur, the chief executive of Socket Media, a marketing and public relations agency.

The “what” turned out to be neighbors who had tapped into their system.

(…)

But they soon began noticing that their high-speed Internet access had become as slow as rush-hour traffic on the 405 freeway.

“I didn’t know whether to blame it on the Santa Ana winds or what,” recalled Mrs. Brodeur, the chief executive of Socket Media, a marketing and public relations agency.

The “what” turned out to be neighbors who had tapped into their system.

(…)

Many home network owners admit that they are oblivious to piggybackers.

Some, like Marla Edwards, who think they have locked intruders out of their networks, learn otherwise. Ms. Edwards, a junior at Baruch College in New York, said her husband recently discovered that their home network was not secure after a visiting friend with a laptop easily hopped on.

“There’s no gauge, no measuring device that says 48 people are using your access,” Ms. Edwards said.

(…)

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Wi-Fi Survey – How do you use Wi-Fi (wireless Internet) technology?

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OSU Wi-Fi Survey: How do you use wireless Internet

As part of the research project for my master, I am conducting an online survey on how people understand and use Wi-Fi technologies.

The goal of the survey is to help improve the design of Wi-Fi by collecting various user experiences.

Whether you have used it only once or use it everyday, every experience you had with Wi-Fi is valuable to this research and I will appreciate if you would take the time to answer my online survey.

The survey is 6-12 min depending on your experience with Wi-Fi and do not require any technical expertise to be answered.

—————————————-
Click here to take the Wi-Fi survey
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Thanks!

Callback Hacks #1: Mobile Phone

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Now that you don’t have to wonder how does callback work?, I can explain some of the interesting designs that comes with this system. By designs, I am refering to so-calls “hacks” or modification made to the original system to support a particular type of users or a new functionality. As callback was an competing alternative to the traditional phone service, it is usually not well received by the national phone operators in most of the countries where it is the most widely used.

So, following a related post by Julian Bleecker (Mobile Phone Usage Idiom — No. 2) and a Times article, Phone revolution makes Africa upwardly mobile , I felt it would be timely to describe one such hack used for mobile phones in some part of Africa.

As I described earlier, the call to start the process of callback (also know as trigger call) usually cost nothing to the customer. So, in 2001, by owning a mobile phone in some part of Africa could make you in some ways a small phone operator. Some people would sign up to the service as agents (getting a commission on all calls made by the customers they signed up). Their customers would come to them when they wanted to make a call and these agents would prepaid their accounts. Customers would then be able to use the agent’s phone to make calls to their relatives. Each of the customers would have a separate account in regard to the callback operator but they will all use the same “source” number, the mobile phone number of their agents. To prevent fraud, all the accounts are to be protected by a password so that a client cannnot use somebody else account to make calls.

This means that a same phone (usually a mobile one) could be used to make tens or hundreds of calls in one day. The advantage of the mobile phone was that the agent could travel with it and go see his customers rather than having to get them to come to a phone shop, especially in rural areas. In 2001, cell mobile phone penetration was still small and it meant 2 things:

  1. People could make a living by working as callback phone agents, owning one or more phones
  2. International calls to landline and mobile phones in most African countries would generally be priced the same

So, the callback system, initially designed to help make cheaper calls by increasing competition in countries with a monopolistic incumbent, became a way for hundreds of people to share one single phone (or a couple). Instead of linking accounts to the actual phone, customers’ accounts were linked to the number required to trigger the call.

Fon Wi-Fi gets support from Google and Skype to build a (sort of) wireless freenet

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As I am doing research on the interaction design issues with wireless networking, I have been particularly interested in seeing how the story with Fon will evolve. I first reported on Fon in October before they launched and I have seen that the movement was gaining some momentum even before being officially launched. but then, I figured out that the solution they were offering was not that novel — Robert Cringely reports on a micro franchisee business model that looks pretty similar — . Experts in the field of wireless and broadband were questioning it too (see Om Malik, Glenn Fleishman).FON wireless

Now that Fon has get major financial backing by company like Google or Skype, this changes the situation. Not only are they getting money but also a lot of free marketing with nearly any major publications talking about Fon. Glenn and OM Malik have posted a nice update on the situation.

I believe that we need to come up with a solution to offer an unified and enriched user experience in regard to wireless networking. The question that stands is not if it is going to happen (I believe it will) but how and when it will happen.

Fon has definitely an opportunity to get it right and has partners that can help it . But there are still major obstacles for it to become successful.

NETWORK SIZE IS NOT EQUAL TO VALUE

The number of hotspots is not directly linked to the value of the network. While Metcalfe’s Law

The value of a network equals approximately the square of the number of users of the system (n2) (Wikipedia)

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