Showing posts with label WiFi. Show all posts
Showing posts with label WiFi. Show all posts

Friday, January 2, 2015

Android Tether - When the Linux Laptop won't connect to WiFi but the Phone does

Linux users and the age old WiFi problem

A Linux die-hard, who'd rather distro-hop, than run any non-Linux based OS. After spending hours trying to figure it out, managed to get the problematic WiFi module to work with the home WiFi router. The laptop connects reliably to the Internet. Life is bliss. Or it is, until the fateful visit with the laptop to a friends or relative's place, a hotel room, or a local coffee shop, that has graciously allowed its patrons to use the Internet connection over WiFi, and the Laptop refuses to connect to the WiFi.

For best impact read the above again, this time in Rod Sterling's voice, like the opening from "The Twilight Zone".

Those familiar with this scenario can feel the frustration one goes through in this situation. I've gone through it many times over the years, and recently, my wife had to as well. The biggest cause for this is that, majority of WiFi modules that are packaged with laptops these days, come with little or no manufacturer support under Linux. That is the unfortunate state of WiFi networking under Linux.

For situations like this, I started carrying with me a USB WiFi module known to work under Linux, as a fail-safe. I sacrifice bandwidth for reliability and it has proved useful over the years. The flip side of this was that, the Android phones I've used over the years, always connected successfully to almost any WiFi network, and I could reliably access Internet over them.

The irony of the situation was that, the solution to my problem was in my pocket all this time, if only I had cared to check it there.  

Android Phone comes to the rescue

Almost all modern Android phones natively provide multiple forms of tethering options: WiFi tethering, USB tethering, and Bluetooth tethering. The good news is, some of these options could come in handy when faced with the WiFi connectivity problems.

WiFi Tethering

WiFi Tethering allows you to share your phone's data connection (3g, 4g, LTE, etc.) with computers that are within range, over WiFi. It transforms your phone into a WiFi Hotspot. The problem with this approach is, you are burning through your phone's data, which doesn't come cheap. Many carriers also impose additional charges to even allow data sharing over WiFi.

USB Tethering

This one took me by surprise. I had used USB tethering before; to share my phone's data connection with my laptops. Setting it up used to be more involved, requiring running a few commands, but newer Android phones have made it seamless to the point, where, it only requires one to check a checkbox on their phone, to activate it. What I hadn't thought of, or tested, earlier was that I could use USB tethering to even share the network that the phone was accessing over its WiFi connection. You do need a data capable USB cable for this to work. You'll know if your USB cable is data capable, if your laptop identifies your phone, and the phone identifies that it is connected to a computer.

Using this option, you'll be able to access your phone's Internet connection over a USB cable connected to you laptop. The connection speed will vary depending on your laptop and the phone capabilities. I was able to get nearly 15Mbps downloads and around 5.5Mbps uploads using this approach with my Nexus 5 phone.

SpeedTest over USB

Bluetooth Tethering

Modern laptops are shipping with WiFi modules that also have a Bluetooth radio. This allows the users to share files with other paired Bluetooth devices, as well as, do some other fancy Bluetooth things. For instance, I can pair my phone with my laptop over Bluetooth, and then all of my phone's sound notifications and other media playing, can be heard on my laptop. Another thing you can do over Bluetooth is share the Internet connection.

Like the earlier two options, you can extend your phone's data connection to the paired device. You may incur additional charges, but it is good to know you have that as an option. You could also, like with the USB tethering option, share your phone's WiFi network connection over to the paired devices - in this case, your Bluetooth enabled laptop.

Don't expect phenomenal speeds. This is Bluetooth we are talking about. My TWC Internet connection clocks nearly 20Mbps over WiFi. But when tethered over my phone's Bluetooth, it drops to mere 0.6Mbps. It's still better than your laptop's WiFi if it doesn't connect at all.

SpeedTest over Bluetooth

Initial issues with Bluetooth Networking

One issue I ran into, while attempting to setup Bluetooth tethering, was that, while the laptop identified the phone's Bluetooth network, and I could transfer files back and forth over Bluetooth, I wasn't able to connect to the Bluetooth network on my phone. Network Manager would show "configuring network interface" message, but always failed to connect.

I later realized that somehow the default configuration of the Bluetooth pair on my phone was interfering with this. The paired connection on my phone, for the laptop, did not expose "Internet Connection Sharing", as an option. I only saw "Media audio" and "Contact sharing", and both were checked. When I unchecked "Media audio" and tried to connect to the Bluetooth network "Nexus 5 Network" from my laptop, I was able to connect to the network. Checking the paired connection's option again on my phone revealed the a new checkbox option, "Internet Connection Sharing", which was already checked.

The Verdict

If you are on the go, with a laptop containing an unreliable WiFi module, you do have options. As long as you have an Android phone (only tested with an Android phone) and a USB data cable or a Bluetooth module for you laptop, you'll be able to stay connected. Of the two, USB tethering offers superior connections speeds, but Bluetooth tether offers yet another fail-safe in case you don't have a data capable USB cable with you. While you may not be able to reliably stream videos from YouTube or Netflix over Bluetooth, as with everything else Linux, it is yet another option.

Friday, December 19, 2014

A 2-in-1 laptop that just works under Linux: Dell Inspiron 13 7000 Series i7347

For quite some time, I've felt the need for an x86 tablet computer that I could carry with me when I was away from my main workstation. This need became a necessity when I started travelling for business, and while my trusty Bonobo Extreme, from System76, was everything I ever needed for a computer to be, it was also a little too bulky and heavy, which made it almost impractical to operate in tight spaces like in a car - while not driving, of course - and in planes. I knew that I needed something that was modern with a tight form factor like that of a Tablet, yet full featured, unlike many Tablets. 

The ideal tablet computer needed to be cost effective and with known compatibility under Linux 32bit and 64bit. I had considered buying the Surface or the Transformer earlier, but since this was going to be a companion computer and not the primary one, and I needed offline storage to install all my software for when I was on the go, the Surface didn't have enough storage or compatibility to just justify the cost, and in addition to the lack of sufficient storage, the Transformer wasn't powerful enough for my needs.

I discovered Dell Inspiron 13 7000 Series i7347 while researching 2-in-1 laptops on Amazon. After spending time researching it, it seemed like it was created with my needs in mind. The additional $100 off the sticker price of the Dell's original $599 made it an even more attractive purchase I could not afford to miss. I was a purchase I did not regret making.
The laptop is very slick and professional looking, which works great, since I intend to take it with me on my business and family trips instead of my more powerful, yet bulky, 17 inch Bonobo Extreme Laptop/Workstation. The hinges on the Inspiron are very sturdy and the laptop easily folds into a tablet. The touchscreen is very responsive. With a 500 GB hard disk at my disposal, I am able to use all my office productivity applications, as well as, software development tools and related services, without any difficulty. Now granted that this model is not an i7 or even an i5, but neither is it an Atom or ARM based. It provides a full computing experience with enough horsepower for smoother operation and functioning.

Installing Linux on it was a breeze. Almost everything worked right out of the box, and the only hiccup under Linux was, the not-so-well supported Wireless/Bluetooth module with Broadcom chipset. However, with little research, I was able to find Intel's Dual Band AC 7260 module, with the proper form factor, that was compatible and well supported under Linux. A version of that module, 7265, is also listed in Dell's specifications document for this laptop as an option. I suppose, if I had bought this directly from Dell, I might have been able to choose the Intel over the Dell Wifi module.

I also made the right call, when I decided to upgrade the WLAN module myself. The laptop is very easy to upgrade manually. The HDD, the RAM, the battery, and the WLAN module, among other things, are easily accessible, once you unscrew the base lid. On their website, Dell provides a Service Repair guide for this model, which provided all the necessary steps needed to help with the hardware upgrade, and that has only boosted my confidence in this machine and it's quality.

I am very happy with the purchase and would recommend it to anyone who intends to run Linux on it.

The 2-in-1 can be purchased from Amazon using the link below.


Note: there are two form factors the Wifi module is available under. You are looking for the smaller of the two.

7260NGW Intel® Dual Band Wireless-AC 7260 802.11ac, Dual Band, 2x2 Wi-Fi + Bluetooth 4.0

The Wifi Module can be purchased from Amazon using the link below. 



Thank you for reading and I hope you enjoyed the article.

Tuesday, June 15, 2010

Ubuntu LTSP over WIFI - TP-LINK TL-WN422G - Update

After spending weeks researching and days trying to implement it, success may not be too far away after all. This morning, on my VM, I was able to finally get to the login screen. I couldn't login, though. However, that may not be such a big issue. I've had similar issue with a regular LTSP client setup and probably a server restart can fix that. I was also able to load the LTSP client on my Fujitsu Stylistic 3500 tablet till the login screen as well. That was very exciting.


Update: Got past the authentication after restarting server and nbd-server service. I get authenticated but yet to see the desktop. So far, so good.

Update: Seems like I get stuck here and can not proceed any further. However, my VM works fine. I'll try changing certain settings to see if that helps.

Update: I'll continue researching this, however, not as aggressively any more. There are so many other things to try and I've only now begun the LTSP experience.
Here is a picture.




Progress on this topic can be followed on the following pages:
Unfinished business: Ubuntu LTSP over Wifi
Ubuntu LTSP over Wifi (Continued)
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G - Update



Monday, June 14, 2010

Ubuntu LTSP over WIFI - TP-LINK TL-WN422G

Couple days ago, I received the two Wireless USB adapters I had ordered. They are both from the same manufacturer, just different speed specs and model numbers and both came with antennas. The model numbers are TL-WN422G and TL-WN722N. The really fun part began when I attempted to load them on my Linux laptop.

I had bought them because I read somewhere that they used Atheros chipset which was also in my laptop's built-in wifi adapter. I had successfully tested LTSP over wifi on my laptop after customizing the initial ramdisk. So, I thought, eh, should be a piece of cake to repeat the steps using USB adapters. Bad judgment. While the built-in wifi adapter used "ath5k" module to work, these two needed "ath9k_htc" module. Now, "ath9k" was stable and packaged with the Linux distribution, however, at the time of this article, "ath9k_htc" was still under development and was not packaged with the operating system. What more? A firmware binary was needed to be present on the computer in order for the adapters to work, a situation I was hoping to avoid.

I did some researching on www.linuxwireless.org and found the right driver modules. After spending few uneventful hours trying to figure out the driver installation on my laptop and on a VM, I was finally beginning to make some progress. Then I started working on customizing the initial ramdisk by packaging the wireless drivers and activating them during the init process. Again, after spending few more very frustrating hours with it, I was able to load the module, load the firmware, activate the wireless adapter, and join the wireless network with WPA security.

The modified LTSP client now hangs while trying to load the network shares. If I recall correctly, I had encountered this in my prior attempts and should be able to fix the issue without wasting too much time.


Progress on this topic can be followed on the following pages:
Unfinished business: Ubuntu LTSP over Wifi
Ubuntu LTSP over Wifi (Continued)
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G - Update

Tuesday, June 8, 2010

Ubuntu LTSP over Wifi (Continued)

This entry is a continuation of Unfinished business: Ubuntu LTSP over Wifi
I have a laptop with a built-in Atheros wireless adapter and an Belkin wireless usb adapter. After some more testing with the customized initial ramdisk, I realized that, while I could use the custom image and easily start the LTSP client with the Atheros interface, on the other hand, Belkin kept dropping the connection and failed to acquire the IP address. I am probably missing something here. However, since I am only beginning to explore the realm of ramdisk customization, I'll pass on trying to get the Belkin adapter to work for now and search for different inexpensive wifi usb adapters to work with.
I'll write more on this after further testing.
In the mean time, I would also welcome any help with getting the Belkin wireless adapter to work.



Progress on this topic can be followed on the following pages:
Unfinished business: Ubuntu LTSP over Wifi
Ubuntu LTSP over Wifi (Continued)
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G - Update

Sunday, June 6, 2010

Unfinished business: Ubuntu LTSP over Wifi

For some time now, I have been working on figuring out LTSP (Linux Terminal Services Project) over wifi. The idea is simple (aren't they all):
  1. Modify the Initial Ramdisk for the PXE boot image to include the Wifi drivers
  2. Update the start up script to load the driver
  3. Connect to wireless router prior to issuing dhcp request
Since wireless drivers are being loaded at boot time, the true PXE nature is lost. Also, the kernel and the initial ramdisk would reside on the client computer's hard disk. However, the computer would boot directly into the LTSP client, using the LTSP servers resources for storage and processing and only using the client machine's inputs and outputs.

When I added the wifi drivers and all the dependencies, the setup did not work. There was still a "not so obvious" component missing. So, I decided to start with a fully loaded initial ramdisk and work my way backwards from there, by removing modules that seemed not necessary. I replaced the /lib/modules/`uname -r` folder of the LTSP ramdisk with that from my desktop installation. Initial tests resulted in a successful startup of LTSP client on my laptop and in Virtual Machines. This also caused my compressed ramdisk image to increase from 8 MiB to about 30 MiB in size.

Now the real challenging part. My laptop is not the intended target for this test. I want to run the customized LTSP client with wifi enabled on old Fujitsu tablets. They have 128 MB in RAM and 500 MHz processor. Yes, very ancient hardware, but that is where the finalized clients will reside. First trials on the tablets failed. After testing on virtual machines with limited resources, I quickly realized that RAM was the problem. Since I can not increase the RAM in those tablets, I'll have to shrink the ramdisk by a significant size.
I haven't worked on this in past few days. Hopefully, I can pick up from where I left in coming days.

Progress on this topic can be followed on the following pages:
Ubuntu LTSP over Wifi (Continued)
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G
Ubuntu LTSP over WIFI - TP-LINK TL-WN422G - Update