Using WiMAX To Replace a Phone? 169
vigmeister writes "I've decided to explore the possibility of using a netbook/MID as a phone while eschewing the services of a cellphone provider. Now that Atlanta (where I live) has WiMAX from Clear, I ought to be connected to the Internet everywhere within the city (once I sign up). Theoretically, this should mean that I will be able to use my netbook as a cell phone. Of course, there are some very real issues to overcome and I am simply putting this experiment together to see if it is something that is realistically possible.
This could possibly extend to uncapped 3G connections (if they exist any more) as well. Are there any obvious problems you would foresee? Is there anything I have missed or any other questions I should attempt to answer in this 'experiment' of mine? A major issue is, of course, the fact that my pseudo-netbook has to be carried everywhere and always left on."
Er... (Score:1, Informative)
How about the fact that you'll be walking around talking into a very slim brick?
You're delusional (Score:4, Informative)
You don't *honestly* think that you're going to get WiMAX coverage everywhere you go, do you? WiMAX isn't magic. It has most of the same limitations that regular 802.11 b/g has. It's an *improvement*, but you still aren't going to get good signal inside of most public buildings.
Forwarding (Score:5, Informative)
Battery Life (Score:3, Informative)
Answered your own question (Score:3, Informative)
You say:
Are there any obvious problems you would foresee?
and then a sentence later:
A major issue is, of course, the fact that my pseudo-netbook has to be carried everywhere and left always on.
I would consider this a pretty big obvious problem.
May want to wait (Score:3, Informative)
Does Clear allow VOIP? (Score:5, Informative)
Re:911 Service (Score:2, Informative)
Re:911 Service (Score:3, Informative)
lol, if push comes to shove, there will be a regular phone around...
I'm sure you won't be laughing when you need 911 and you realize you were wrong.
Done it (Score:4, Informative)
The CP Lawn Bowling Club in Victoria, BC has done this. WiMAX -> Buffalo AP -> Linksys PAP2T -> SIP provider. Bringing the monthly bill from $54/month with Telus on copper pair, to $35/month for unlimited long distance and broadband/wifi as well. http://cplawnbowling.org/ [cplawnbowling.org]
Re:Problems (Score:2, Informative)
A chapter of Malcolm Gladwell's book Blink examines how people can make seemingly obvious errors in situations where they feel threatened. Their "animal brain" kicks in, and higher functions are pushed aside. As a result, would-be callers often hit the wrong numbers, forget to hit Send, etc.
One expert recommended that everyone spend some time practicing dialing 911 so that their brains are adequately prepared to do it under stress. It's an odd image but it might be a good idea.
Re:Problems (Score:3, Informative)
While you are being sarcastic (and knew exactly what he meant) you should try to also actually inform him of the problem:
In order to "dial 911" over VOIP and get connected, the VOIP provider needs to be able to route your call to a PSAP (Public Safety Answering Point). The challenge is knowing which PSAP actually applies to you. You need to inform your VOIP provider of your location so they can choose the appropriate PSAP. Of course, that is if they even offer E911 service at all. Most VOIP providers don't seem to offer it at all right now. When you sign up for service, you need to be aware if they offer it. Most of the time it seems to be just a dollar or two more.
I would expect the vast majority of the so-called "free" SIP providers don't even offer E911. Which I would also expect would be the most popular choice for people choosing this method of communication as "cheap" seems to be the whole reason they are doing it.
Your other challenge is that you are wireless in this scenario. There is a scheduled deployment, and progressive requirements for cell phone carriers to provide accurate location information to the PSAP when they connect the call. They obviously know which one is closest since they known which cell tower you are communicating to. That's how they get the correct PSAP for you. However, the PSAP wants to know WHERE you are much more accurately so they can send an ambulance right to you instead of forming a search party.
In this scenario, you are not connecting to a cell phone tower that can triangulate your position automatically or choose the appropriate PSAP. You are using a netbook, or some other device, connected to a wireless Internet connection. AFAIK, there are no technologies or methodologies in place for you to transmit your current location (assuming you even have GPS on the device) to your VOIP provider, which would then provided to the PSAP.
If you contract for E911 service with a VOIP provider in San Fransisco, use your San Fransisco address with E911, and then make an emergency call while in Los Angeles.... you will be connected to a PSAP in San Fransisco.
So the first challenge is just getting the E911 service with your VOIP provider. The PROBLEM is going to be getting accurate location information transmitted to the PSAP when you are connected, or connected to the appropriate PSAP in the first place.
Logic would tell you that while talking to the emergency operator you can just tell here where you are. Unfortunately, if you are 100 or 3000 miles away from him/her it is going to be quite difficult for them to transfer you to the appropriate PSAP. It would certainly take some time, which most people talking to 911 don't have.
WiMax isn't as 'full coverage' as you might think. (Score:4, Informative)
Portland, Oregon, also has WiMax through Clear. There are decently large sections of Portland (including my house,) that do not have WiMax coverage; and larger sections with very spotty coverage. Admittedly, Portland is a much "hillier" city than Atlanta, but it only stands to reason that some parts of Atlanta would have coverage that leaves much to be desired, as well.
The 911 problem others mention can be resolved by picking a VoIP provider that has 911 service; or by manually bookmarking your local phone number for emergency dispatch.
WiMAX was designed for this, implementations lag (Score:5, Informative)
WiMAX was designed to handle VoIP traffic, and has specific traffic categories on the airlink for isochronous flows, like RTP and other VoIP payload streams. Unlike something like Ethernet, which is CSMA/CD (carrier sense multiple access, with collision detection), traffic is scheduled by the carrier network. For uplink data, your WiMAX card goes through a process of requesting bandwidth on what amounts to a hailing channel, and then gets a bandwidth allocation it can use. In theory, a small but constant amount of bandwidth can be allocated for VoIP at the airlink level, resulting in low jitter, low latency, and low frame loss.
There are a couple of problems with this.
The first problem is that not all WiMAX cards on the market today (in fact, quite possibly none of them) have sufficient sophistication in their device drivers and microcontrollers to send the RTP (or Skype, or whatever VoIP protocol you're using) packets on an isochronous service flow while the balance of the packets travel on a general-purpose service flow. As a result, the RTP (etc) packets have to compete with whatever else your machine is doing, either stuff you're initiating with the browser, or background things like checking email or updating the Vista weather widget, or checking for updates of one kind or another. It doesn't help matters that no operating system has a network stack that implements the service flow concept.
The second problem is that low-speed isochronous flows over the WiMAX OFDMA airlink depend upon sharing a fairly large timeslot with other users transmitting simultaneously on the uplink using a different set of carriers, at least if the system is going to be economically feasible for the carrier. Allocating an entire timeslot often enough to keep the delay below half a second or so would result in considerable wasted bandwidth, so the idea is to have users share a timeslot by have each one use only a fraction of the available carriers. Decoding the resulting burst at the base station then depends upon maintaining orthogonality between OFDM carriers, which means that exact frequency synchronization is required between multiple users. While each user's WiMAX card synchronizes its clock with the base station, doppler shift due to changes in speed or direction or a changing multipath environment can change the received frequency at the base station enough to compromise orthogonality and make the burst impossible to decode.
The result of all this is, from your perspective, is that your VoIP traffic could be jittery and have long delays and high packet loss, especially when the carrier's network is heavily loaded.
Re:Does Clear allow VOIP? (Score:4, Informative)
Well first off Skype sucks. Not trolling, I promise. It just really sucks for quality and that is my own experience and that of several others. Skype also does require you to "pony up" more money to connect to "regular" phones. So it's not as free of a solution as one might think and I believe the person in the article wants to connect to the regular or traditional phone systems.
As for the blocking the easiest way to bypass that is VPN. All of the VOIP setups I have created and maintain use VPN for all the SIP/AIX traffic between the branch offices and the provider. Assuming this person has a computer that he can leave on at home, setting up his Netbook/MID to route the traffic across the VPN and then ultimately to the VOIP provider is not terribly difficult.
I realize that would require some expertise, and not everyone would have another computer or network to VPN too, just pointing out the blocking can be bypassed.
Re:You're delusional (Score:4, Informative)
Latency? (Score:2, Informative)
You might want to stop by a WiMAX booth in a mall like I did and try and make a few calls and make sure everything works as expected. They let me do pretty much whatever I wanted (in fact, the sales guy pretty much left me alone).
Re:You're delusional (Score:2, Informative)
Actually Canada has a WiMAX network that covers just about the same network as cell phones. Each cell tower (from Rogers and Bell) is also part of a nationwide WiMAX network.
Unfortunately you have to use their proprietary modem or usb dongle.
Your biggest problem is CSMA and VOIP (Score:2, Informative)
For example, an 802.11b network can handle ~140 simultaneous Skype calls in theory, but only about 6 in practice. For a more detailed analysis, see this paper [usenix.org]
Re:Wrong tool for the wrong job. (Score:4, Informative)
Actually the real question is why didn't the poster spend 1 minute on Google. Just search skype wimax phone [google.com]. Fourth link down is a page about the N810 WiMax edition with instructions on how to install Skype [skype.com]. Searched ebay and found two n810 WiMax's for a bit over $200 [ebay.com].
I imagine a n810 running Skype would work better than carrying around a netbook everywhere. It's also easier to hold to your ear than a netbook....