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Using WiMAX To Replace a Phone?
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."
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.
Are there any obvious problems you would foresee?
How are you going to dial 911?
Unless you barely use your cellphone, you'll find that the netbook's battery is
your biggest limiting factor. Particularly if you use a bluetooth headset so you aren't walking around
with a cabled headset plugged into the netbook. There are 802.11 based SIP phones that can serve the same purpose.
I think an important thing to consider is the ability to forward your number. I'm thinking of doing that in general. If I have one number which I can forward different places, I can give that out to people who want to call me and I can have it forwarded to a prepaid cell phone, my work phone or other devices as needed at any particular time. It makes your idea much more practical and I think it's how people will do things in the future. It also helps enable more competition in the market for mobile phone devices.
Having to leave the netbook on with an ACTIVE WiMAX connection. Enjoy your cell phone with a 2 hour battery life, when not using it to talk.
... and in the DRM, bind them.
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.
Because they're not ubiquitous. You will end up somewhere where coverage isn't so great for your new protocol. If you can handoff to an older protocol, you will keep your connection. So this is why even a few years ago you could get Verizon phones that still supported AMPS, why every phone that supports EV-DO also supports 1X (and older standards), and why every phone with WCDMA/HSDPA/HSUPA/etc still supports plain old GSM/GPRS/EDGE.
It's also why it doesn't make a lot of sense to have a WiMAX only phone. You need at least WiMAX+GSM, or WiMAX+CDMA1X. You need to be able to hand off to the older interfaces. And probably you want to support everything... WiMAX when it's available, HSDPA or WCDMA when that's available but WiMAX isn't, or GSM/GPRS/EDGE when that's all that's available.
Or maybe you never leave downtown Atlanta. Then maybe WiMAX-only would be fine, assuming you trust the reliability of the relatively new network.
-- Erich
Slashdot reader since 1997
To use a netbook as a true phone replacement, you need battery life of 24 hours (what happens if a call comes in while you are switching battery packs?) Also, what is the battery life of your bluetooth headset? In addition, I believe most netbooks shut themselves down when the lid is closed; you need to either figure out a way to defeat this or figure out a way to carry it around with the lid open.
I've abandoned my search for truth; now I'm just looking for some useful delusions.
I use Clearwire's regular wireless internet here in Seattle. They block Skype traffic to promote their own VIOP plan for an extra $10-15/month. They might not let you use your netbook as a cell phone without ponying up extra $$.
Funtime Candy Wow! - my plan for eventually conquering Japan.
Problem solved...
http://www.thinkgeek.com/gadgets/cellphone/8928/
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If VOIP is being offered a as service then the voice provider is required to implement 911.
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.
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/
Are there any obvious problems you would foresee?
"Oh my god, someone call 9-1-1!"
"Hang on, let me get my computer out of suspend...
And put my headset on...
Ok, I am dialing...
Hello, yes, emergency-- What? You are the 9-1-1 dispatch center where? Tulsa?"
I like this idea, but I am more enamored by the idea of a Wimax enabled phone. HTC will be offering a Wimax Android phone soon I believe. This is cool, because the it's carriers can't lock down the phone since it's OSS. A even cooler solution would be deploy your own Wimax router at home and have free Internet/Voip service miles from home. When you are out of range you could use a prepaid phone.. I do think laptop Wimax Voip solution would be good especially for outgoing calls.
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.
Another non-functioning site was "uncertainty.microsoft.com."
The purpose of that site was not known.
If you're mobile, you wouldn't care if 911 is supported - the operator wouldn't have your location. You'd carry around your old cell phone with no contract or service for that job.
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.
Hello, yes, emergency-- What? You are the 9-1-1 dispatch center where? Tulsa?"
Or just dial 404-658-6666, which is the direct line to City of Atlanta 911. (Useful to know when your cell phone happens to connect to a tower outside the city limits, and 911 routes your call to the county emergency services, but the county won't send anyone to your address, because you live inside the city limits, and your call is disconnected when the county operators attempt to transfer you to the correct call center ..... four times in a row ..... )
It seems like the arguments against this can be put in 3 categories. 911, battery life and coverage.
I would think that if you are viewing this as a "cell"phone replacement then it would obviously fail on all 3.
I remember being able to live without a cellphone. In fact, I miss it. I find it very annoying that in our cellphone enamoured society my friends and relatives feel "entitled" to talk to me whenever, wherever I might be. I don't want to talk to someone as I go through the checkout line in the grocery store. I find it annoying to try to understand someone who will not speak up when I am driving my Jeep. It's loud in there. Let alone the safety issues! I'd rather call people back when it's convenient for me. Just like I would have with an answering machine and a landline about 12 years ago. Does this make me old? I am only 29.
That in mind I too have considered what the author is asking though I would use a more portable form, some sort of PDA rather than a netbook.
I would keep separate power adapters in my office at work, one at home and a third in my car. Most of the time I would be in one of those places and could plug it in. Don't want to be tethered to the plug? Use bluetooth! If I don't get a signal in my car then oh-well. I know how to change a tire! That about takes care of the power problem. It just doesn't have to be on every moment I am not in one of those places. If I need to make a call, that's when I would turn it on and use the battery.
As for coverage... wifi at home and work are easy. Your mileage will vary at work but I doubt many on this site don't have it at home. Anywhere else it works... that's just a bonus.
Think you have too much of a social life to not be always connected? Do you think you will miss too much because you're out? I think not... you are on Slashdot! Seriously though, I was a college student with one of the busiest lives I knew just before I got my first cellphone. Missing calls didn't stop me, if I missed it then I was already busy! If I missed too many calls then maybe I would have ended up at home, but then I wouldn't miss the next call. See how that works?!
Now, 911. This issue has been brought up against every form of VoIP since the begining. I have to ask... does it really matter that much? Honestly, I don't know the answer to this but don't the 911 operators have the ability to transfer to one another quickly? If not then this is a problem the public should be crying to see addressed! What if a call was coming in via radio or some other third party method where the person making the call is not in the same local as the emergency. Hasn't there always been a need for 911 calls to be transfered?
I'm surprised I'm seeing not a lot of comments here about latency issues. I live in Baltimore and I also happen to live in an area where we're stuck with a single provider for broadband internet (a condo with an exclusive contract to a horrible, horrible ISP. No, not Comcast or Verizon... MDU Communications). Before WiMAX came along, I had no option but to stick with the horrible ISP or deal with dial up. When I found out WiMAX was available where I live, I was excited. I went to one of their booths at a mall and played with it, but I was a little concerned with the latency. I was pinging google and wasn't getting a response for ~250ms. This isn't horrible for such a service, but even MDU gives me less than half that for most sites.
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).
Good point. Perhaps we should also all become heart surgeons, midwives, and bomb disposal technicians. After all, if every single person doesn't do every single thing to prepare for every single rare possibility, we are all totally and irrevocably doomed. DOOMED!
How do you feel about people who dare leave the house without carrying a cell phone at all? They are also unable to call 911. Do you spit in their faces as they pass, or just silently seethe at them, knowing they'll burn in hell for their negligence?
P.S. I don't believe any voluntarily non-vaccinated person had the thought process you describe. They don't do it because they think it'll make them sick, or that it will let the CIA read their thoughts.
"Patriotism is your conviction that this country is superior to all other countries because you were born in it." -- GBS
"Hang on, let me get my computer out of suspend...
And put my headset on...
I'm going to put on my robe and wizard hat...
Cell carriers used scheduled access to the wireless channel, which provides guarantees on bandwidth and latency so that your speech is understandable. 802.11 provides random access, which is great for bursty Web traffic but terrible for voice when multiple people use it simultaneously (and undoubtedly you would not be the only one using VOIP over your WiMax AP).
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
0 < all too fucking common <= 100
Have had this discussion with Clear already. You can roam anywhere on their networks - as long as you're in Atlanta or Portland Oregon, the two cities where they have a presence.
Was thinking about WiMax as a solution to mobile connectivity for my laptop, until I realized I'd have to set up different service in the different cities where I want to work (and would have to wait until some of those cities have WiMax in place). FAIL.
Not like I want to pay for 3G, either.
I figure in 10 years, a lot of this gets sorted out. I'll put the MacBook Pro on standby 'till then, k?
Yes, you can actually. I got the apple earphones(needed to replace old ones) & mic set from my local mac store and I hooked them up to an ipod touch with the skype app and was able to make calls easily. This was using only 802.11b/g connections that were open where ever I was located. The biggest problem was spotty wifi connectivity and coverage. Also since I ride a motorcycle I was more worried about having access to emergency services, so I didn't go with it as a solution to totally replace my cellphone.
I could see that if it were economical, you could have all calls go to skype & skype-voicemail and talk when you're close to a wifi connection. While also having a prepaid cell phone for emergency calls. I was very close to doing this but since I'm on a family plan and my cell phone is only $10 extra it wouldn't really save me anything to go that route.
www.rdex.net
When I first moved out of my hometown to another city after graduating, my first concern was staying in touch with friends and family without using my phone to save on long distance calls. I also wanted them to be able to call me without extra costs. So here's what I did. Using my laptop I was able to get a full "voip" line using Skype with the Skype-Out service and getting a phone number through DID Worldwide. Skype-Out costs around 3$ a month and the DID number costs 5$ a month. This way for approx. 7$ I was able to make and receive calls through Skype. To go a step further, you could get a Skype Phone so you won't have to carry around a netbook or a laptop.