Correction

The wifi network which my friend was using on the bus is not the true wifi. It turned out to be that the core netowrk was CDMA, and the access point was wifi. It works out like this: An antenna is mounted on the roof top, and a CDMA modem is connected to it. This provides the network connectivity and it is distributed using a wifi router. So simple. Isn't it ?

CDMA is a cellular network with a frequency reuse factor 1. It's limited data speed (144 Kbps)and soft capacity narrows down its use as an substiute to brodband internet access technology. Nevertheless, the reach of CDMA network vouches its use, and now many USB devices are available, for quite cheap, that can give you a good internet experience. I will talk about the CDMA in my next blog.

Thanks Carl for the prompt correction.

WiFi on the bus

Recently my Swedish friend, who now lives in Tallin, told me that he was able to access internet inside the bus. It was the SEBE wifi network that he was logged on to. It intrigued me, and so I did a little research. It turned out be that Estonia is the only country in the world, now popularly being called as E-stonia, which has almost 75% of its area covered with the WiFi network. You can easily find a hot spot in a cafe, restaurants, hotels and on streets. But being able to surf uninterrupted internet on the bus is something really cool.

Wifi (802.11) has traditionally evolved as a nomadic wireless access in the ISM band (2.4 Ghz) with limited range. Typical range of a Wifi network is around 100 meters (20dBm power). So if you to cover, lets say, 10 km stretch on a highway than, at least, 100(10000/100) Wifi access points will be required. Of course, power can be increased but its more of a regulatory issues. The biggest challenge with the Wifi is mobility. When you move from one coverage area to the another, your IP address gets changed. This breaks the IP session and the network connectivity gets lost momentarily. Therefore, if you are chatting on a Yahoo or Msn messenger, you would notice a short disconnection.

Although a new standard of the Wifi has come up (802.16n), which supports mobility through "hand offs". In a hand off IP connectivity remains unaffected even if the access point changes. This is done at the back hand network. But this is largely to be seen; how many countries would adopt it as, other broadband wireless technologies like, Wimax and LTE are also picking up.

Hat's off to E-stonia!

Ps: More on the CJ blog

How to create a Bluetooth Personal Area Network ?

This is the first in the series of blogs that will tell you -- how you can use the wireless to simplify your life. Bluetooth is a piconet access technology. Its works in a free licensed band of 2.4 Ghz (ISM), which means that it can radiate to a relatively short distance. Typcial range of a bluetooth device is 10 meters (Class II device), but I have also seen one that can radiate upto 100 meters (Class1 device). Its in your phone, in your computer, laptops and car stereos. Everyone must have used it to transfer mp3, video and calls (using headset) between various devices.


Today I am going to tell you- how you can share internet over bluetooth devices. It all started when I needed to share my internet connection among my peers . We were all poor people ( we did have laptops though :) ), and we could not afford to buy a wifi wireless router. But we all had the bluetooth modem within our computers, and thats where it stuck me to use it for net sharing. Bluetooth can be an ideal replacement of wifi, if
1.) You live in a small house (not greater than 100 meters in width :P )
2.) Have computers or any device with bluetooth modem
3.) You prefer spending money on Beer and Pizza's instead of wifi router

So, lets start. First, you need a computer that can act as master. Your Lan (Ethernet) cable would be connected to the master computer. The other computers will act as slaves. Now, pair all the slaves with this master using a passkey (you know how to pair right?) . Enable the internet sharing (this is important!) by selecting the "Allow internet other network ....." under the advance tab of local area connection in the networks settings. Now go to a slave's computer bluetooth control panel and click on "connect to PAN area network". Thats it! you are now connected. It is as simple as this. Open the browser and start surfing.

Remember one thing - as more and more slaves gets connected, surfing speed will get reduced, as the bandwidth will be shared. Bluetooth PAN is not suitable for internet speed over 1 Mpbs (I would say upto 500 Kbps) due to limited bandwidth. Nevertheless, it gives a fairly good mobility, and its short range gives you the freedom from the sleepless nights of eavesdroping and misusing of internet by hackers. So make you own pan right now and experiance the freedom of being wireless!

The Android's dream

No its not about any Japanese Android! Its about the "Android", the Google's new operating system for the mobile phone's. Well, it seems like, its not just an another mobile OS like Symbian or Windows. First, it is developed by Google, which has the reputation of bringing innovative and exciting products and secondly its open source which says it all.

HTC would be taking out the android OS into their new phone, christened, "HTC Dream". Today They have gotten the approval from FCC but hopefully it will not be the only one, more will follow. Little digging into it revealed its superiority to other OS :

a) It promises to be an open platform just like Linux. Remember that Iphone is still not an open source and I guess won't be in the future.

b) Android won't be limited to one manufacturer or (hopefully) just one carrier.

c) Android will operate on multiple devices that will offer varying designs and features.

d) Android (HTC Dream) will have application like multimedia messaging, voice dialing, and video recording, all of which are lacking on the iPhone.

e) Support from Google

I heard that Android will also support 3G and Edge networks along with usual wireless connection like wifi and bluetooth.

I have been waiting for a product like this because, in the past, whenever comes a software bug in the phone, we were left at the mercy of the phone manufacturer or microsoft (for Window Mobile Phones). I am still not able to figure out why skype doesn't work on my HTC touch! Now all this will change with Android. I could just dive deep inside the source code and figure out the problem myself. Thanks Google! Visit code.google.com/android/what-is-android.html

Back again !

Hello! I am back. Sorry, I was very busy for the last one month and I also went on a vacation to Singapore and Malaysia. These are some amazing countries of Asia with so much to offer.

All right, back to the business but first something about Apple iPhone 3G. I have Google desktop on my work computer and I get regular news from the Google. Lately, I have been getting lot of criticism about the device. Some said that its updation sucks, some said that the third party application installation was a headache etc. I think that by following the third party application development, apple is slowly migrating toward the path that Microsoft once took with windows. I don't like it personally. I always rated apple to be better and innovative than Microsoft. Nevertheless, my advice is to be careful while purchasing the device.

Okay, you have more things to see on this blog now. There is a CNN feed and a small poll on the right bottom corner of your screen. The CNN feed will keep you updated with the latest from the tech world. There is also a skype widget that connects you to me any time . So nice isn't it ?

I assume that all of you have atleast one GSM phone with you. Yes, the mobile phone with sim card inside. GSM (Global Service For Mobile Communication) is the second generation mobile technology i.e. 2G. It was evolved as a voice telephony service which also supported very low rate data application (9.6 Kbps or 1.2KBps) like sms and fax. This data rate is much much slower than what your readng this blog with in your computer(I am sure!) . With this speed, you can download a typical mp3 song in, lets say, 83 minutes!!! Scary isn't it ?

Well, in theory, the GSM was only designed to support the small data intensive application like SMS and fax. But as the penetration of mobile phone increased, the demand of data rates also increased. Specially, after the advent of internet and its popularity forced people to migrate from the simple sms services to heavy applications like emails and mms. This simply put more burden on the poor GSM. Something new was bound to come. So came the 2.5 G which is nothing but the addition of GPRS (General Packet Radio Service) to the existing GSM. GPRS increased the speed from 9.6 Kbps to 114 Kbps, similar to IS -95 or CDMA 1x RTT. But this wasn't sufficient as more and more data intensive application poured in. Engineers felt themselves under tremendous pressure to increase the data rates even further. So , after 2.5 G, came an intermediate evolution which is known as 2.75 G. In GSM terminology it is called the EDGE (Enhance Data for GSM Evolution). Data rates were shot up to over 300 Kbps. This was something. If you are a frequent user of mobile internet in the EDGE network, you will notice a small E symbol along with the signal bars. Thats EDGE for you !!

But the real breakthrough came with the evolution of 3G or the third generation technology which has changed the face of mobile internet. Reports have claimed the data rates in excess of 2 Mbps. 3G can be attributed to many technologies like UMTS, LTE, HSDPA, HSUPA, wifi and wimax. With this speed you can have a live video conferencing, watch a live streaming like you tube. You can also send pictures, play game, check email and what not. I am yet to experience 3 network in India. But I guess its coming soon. So, in summary
Generation Technology Data rates
2 GSM 9.6 Kbps
2.5 GPRS 144 Kbps
2.75 EDGE 325 Kbps
3 UMTS, LTE 2 Mbps
WIMAX, HSDPA, HSUPA

If you want to see the real difference between a 2G and a 3g network than I would suggest you to go to Apple website (http://www.apple.com)/and see the Steve Jobbs keynote on IPhone 3G where he showed a little demo on the downloading speed with the two networks.