HOWTO hack your Android phone and turn it into a WiFi access point fed by the 3G modem

If you have an Android phone, you probably have an unlimited data plan or something like it -- but the telcos and Google have done their best to keep you from using the phone as a 3G modem with your laptop (it's "unlimited" provided you don't try to use it with a full-sized computer).

The nice thing is that the Android OS is based on free/open Linux, and hackers have extracted the security information necessary to load your own OS on your phone. With an open, hackable OS and an open bootloader, the tethering problem is simple to solve: just install your own OS that includes all the same code as a factory-fresh G1, with the anti-tethering stuff deleted. You can even bridge the 3G to the WiFi in your phone, turning your G1 into a self-contained all-wireless WiFi access point (bring along a USB cable anyway, since you need to keep the damned thing charging or your battery will croak in ten seconds flat).

Danny O'Brien describes the moment that drove him to cracking open his G1, and recommends a HOWTO for getting the job done. I know what I'll be doing when I get home!

So it was being stuck without wifi in the Library of Congress the other week that finally made me decide to overwrite the T-Mobile firmware on my Android G1 with something with root access. I was talking with the US Copyright and Patent offices about how to improve access to copyrighted material for the reading disabled (in the hopes, partially, to encourage them to support the Treaty for the Visually Impaired at WIPO the following week).

In the end, I chose to install JesusFreke's distribution of the Android OS, which now has a great little utility to manage who gets root on your phone (each application's request is intercepted, and you, as user, get to allow or deny it). This tethering application is incredibly easy-to-use, and lets you share your 3G connection via wifi or bluetooth (I haven't tried the bluetooth). You can WEP encrypt the wifi connection, or allow access to only selected users.

Of course, next time I go to the LoC, I'll be sure to keep the wifi node open. I wouldn't want the MPAA guys doing without!

How To: Root Your G1 And Install Android 1.5 Cupcake (via Oblomovka)


  1. This seems like a good way to convince cell phone companies to stop offering unlimited plans. I somehow doubt that most 3G networks were designed to handle a multitude of open wifi APs running on them, and so this seems actively abusive and likely to get one’s service terminated.

    While ISPs offering unlimited plans that aren’t actually unlimited are falsely advertising and at fault, it seems to me that cell phone companies with unlimited non-tethering data plans are trying to make a plan that is convenient for cell phone users, and don’t imply that the plans should be usable on general devices, much less on multiple devices. Though the hack itself is interesting, it is unfortunate that people actually intend to use it as though there is nothing wrong with doing so.

  2. WA, you have a point. But I think it’s based on the idea that it’s wrong because the carriers say it’s wrong.

    I believe the Japanese market proves that mobile broadband is technically and economically viable, if only in dense urban areas (which is a great start).

    US carriers just aren’t ready to open the floodgates, for some reason. I think that reason is greed and power.

  3. If they don’t have the capacity to handle the opening of the floodgates of everyone doing it, then they have to limit access to prevent scalability problems. This is classic management of limited resources. Their business plan probably doesn’t include having enough bandwidth to handle unlimited access. Even when I had a 3G card with AT&T, I was limited to some extent as to how much I could use it in a month. Not a very good “deal” really.

  4. Or get a phone from a manufacturer that doesn’t bend over for the carriers. Unlocked.

    Step 2: Install Joiku Spot. DONE.

  5. I somehow doubt that most 3G networks were designed to handle a multitude of open wifi APs running on them, and so this seems actively abusive and likely to get one’s service terminated.

    Keep drinking the Kool-Aid.

    Wireless service providers aren’t underprovisioning because of technological limitations, but because it’s a greedy way to cut down on their bandwidth costs.

    Though the hack itself is interesting, it is unfortunate that people actually intend to use it as though there is nothing wrong with doing so.

    “Wrong”? As in, you believe this is immoral?

    Sorry to burst your bubble, but this is exactly how end-users spur innovation.

    (Remember the iPhone? Without jailbreaking there’d be no apps; now the AppStore is Apple’s biggest selling point.)

    I say, it’s about fucking time! I’ve been wondering aloud why this feature hasn’t existed in WiFi-capable smartphones for over a year.

    “Tethering” via Bluetooth seems needlessly complicated, when practically everything understands how to connect to a WiFi access point (AP). With an iPhone or BlackBerry that includes WiFi, having “Internet sharing” from the data plan to WiFi is the obvious solution.

  6. Furthermore, having your WiFi-capable phone act as an access point makes devices such as the Mi-Fi redundant.

    WA @3, if the wireless telecoms were so opposed to having open APs on their 3G networks, why would they specifically offer a device to do precisely that?

  7. I think it’s hilarious that I can get a series of bits to display wikipedia on my phone. I can save it to my micro-sd card, put that in my laptop, and open the file. No problem. But the moment I send those bits across a wire or through the air to my laptop, I’m breaking the rules.

    Then I see that dbag on his verizon netbook peddling ANOTHER data plan, and it all makes sense. Bigger screens require bigger tubes.

  8. @6:

    It’s wrong in the sense that you are violating the agreement you made with the carrier. You shouldn’t have done that if you didn’t intend to abide by the terms.

    Also, as much fun as it is to haxx0r your phone, for the same price you can order the Google Dev phone which is not tied to a carrier and allows you to flash it with whatever you want out of the box. It’s an HTC Dream, too, but has a cooler back cover than the G1.

    Finally, as a T-Mobile subscriber I can tell you that their 3g service is horrid and the G1 doubly so. If you plan to use this as your primary internet connection it WILL end in tears, as it will break unexpectedly several times a day.

  9. Anyone know of a way to tether without needing root access? I am curious but not willing to make such changes to my phone.

  10. Not to diss the hax but you could buy a Nokia or Samsung phone running Symbian S60 and run the free Lite version of Joikuspot. No hacking involved, install, open, turns your phone into WiFi point. No fuss, no muss.

  11. @9:

    “For the same price” as an unlocked phone with no SIM card, assuming you can’t find a discount somewhere, sure.

    I got my phone for $150, with contract (and since I already was a loyal and happy T-Mobile customer, that was hardly a burden)… and rooting it is free.

  12. LudditeMike @9

    Ok, granted. But those terms are ridiculous. They violate the end-to-end principle / dumb network / net neutrality, by specifying that only particular devices or purposes can be used for Internet access. (Hence Cory citing Carterfone @5.)

    Just as copyright infringement via downloading unencumbered movies and music online has forced the media cartels into eventually begrudgingly giving up on DRM and attempting half-assed compromises such as Hulu and the iTunes Store, these hacks by customers will ultimately compel wireless carriers to act like a real ISP and provide neutral bandwidth, such as 42Mbps with HSPA+.

    T-Mobile Terms and Conditions

    1. Permissible and Prohibited Uses
    Your Data Plan is intended for Web browsing, messaging, and similar activities on your device and not on any other equipment. Unless explicitly permitted by your Data Plan, other uses, including for example, tethering your device to a personal computer or other hardware, are not permitted.

    Examples of prohibited uses include but are not limited to: (a) server devices or host computer applications, including continuous Web camera posts or broadcasts, automatic data feeds, automated machine-to-machine connections or peer-to-peer (P2P) file-sharing applications that are broadcast to multiple servers or recipients, “bots” or similar routines that could disrupt net user groups or email use by others or other applications that denigrate network capacity or functionality; (b) as a substitute or backup for private lines or dedicated data connections; (c) any activity that adversely affects the ability of other users or systems to use either T-Mobile’s services or the network-based resources of others, including the generation or dissemination of viruses, malware or “denial of service” attacks; (d) accessing, or attempting to access without authority, the information, accounts or devices of others, or to penetrate, or attempt to penetrate, T-Mobile’s or another entity’s network or systems; or (e) running software or other devices that maintain continuously active Internet connections when a computer’s connection would otherwise be idle, or “keep alive” functions. For example, you cannot use a Data Plan for Web broadcasting, or for the operation of servers, telemetry devices and/or supervisory control and data acquisition devices.

  13. ACEJOHNNY – US carriers really aren’t ready to open the floodgates because the tubes would clog. 3G on my iPhone gets SLOW (and sucks battery with all the retransmits) in cities. Out in the ‘burbs, it cruises. I can stream in the car without a hiccup.

    FWIW, I did this with my 3G RAZR two years ago. I still carry it around in my laptop bag, and if I really need tethering all I have to do is pop in the SIM from my iPhone.

    I’d recommend using USB from the mobile to a laptop/netbook, and running the wifi sharing from there. You’ll get better performance, the much larger battery in the computer keeps the phone charged, and you can filter/firewall/throttle/monitor stuff. Or, buy a WWAN card and swap in your SIM.

    Don;t overuse it, and they won’t care you don’t have a tethering plan. Also, don’t tether over bluetooth, your battery won’t like it.

  14. Also, don’t tether over bluetooth, your battery won’t like it.

    Actually, battery life is the only legitimate reason why you would want to tether with Bluetooth rather than WiFi. (Low power consumption is the whole reason why Bluetooth exists in parallel to WiFi.)

    However, significantly improved batteries in smartphones is a major reason why WiFi is able to be supported in them in the first place. In practice, as with Verizon’s Mi-Fi, you’ll get a several hours of WiFi before the battery runs down, and if you’re worried about that, you can just have it recharge via a USB cable at the same time. (Presuming that you’re sitting down at a table with your laptop or in your car while using it.)

  15. Unlimited data,
    my god, such a thing, such a thing is unknown in this part of the world.
    1-3gig are the highest plans available the lowest, ha well they go right down to 20 megabites.
    Australia feels such a very long way behind sometimes.

  16. ZUZU – I was referring to Bluetooth vs. USB if that’s what your phone supports for tethering.

    If your phone supports tethering over Wifi, you don’t need to do any of this, it’s already an access point!

  17. There is a program called PDAnet that works well to tether without root access. I have been using it for 2 months, though I haven’t tried it in the last few days since Cupcake showed up.

  18. bluetoooth exists with the concept of removing wires between a multitude of technologies. wifi is specifically for the networking concept. power consumption may be part of the equation but the driving force is scalability based on complexity. it’s like comparing apples and oranges, yes they are both fruits but….

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