New face of terrorism

It has been a terrible week for the Mumbaiker and for India . On the fateful night of Wednesday, coinciding with the movie on terror ‘Wednesday’, Mumbai was terrorized
by 10 outrageous terrorists. Clad with AK-47 and hand grenades, they walked freely on the streets of South Mumbai, reminding the haunting pictures of US military patrolling in Iraq.

It was uncalled for, as with any other terrorist attack, and it left the city of 18 million resident paralyzed. South Mumbai is a popular destination among the foreigners. Its active night life and star rated hotels makes it a sought after destination in India. It is also my personal favorite destination.

India has witnessed many terrorist attacks in the recent past, ranging from Islamist extremist attacks in Delhi and Ahmadabad, to the moist attack in South East India. But this time it was unusual in the way it was executed. For the first time terrorist used the sea route to penetrate India. They docked at the Gateway of India, split into a team of 2, marched toward Mumbai. They fired indiscriminately on the people, sterilizing the police and made a mockery of the Indian home land security.

They soon barged into some important places like the iconic Taj Mahal hotel at Colaba, hotel Trident Oberoi and Nariman building, a Jewish abode, showing the young and brutal face of terrorism. Soon, within 59 hours before Indian National Security commandos and marines corps could over power them, 152 people were killed including 22 foreigners and around 400 people were injured. A two year old Jewish Kid ‘Moshe’ was also left orphaned on his birthday.

Report says that they were all Pakistani’s. One captured terrorist Kazam(Inset) confessed that they were trained in Pakistan by an ex military commander. They went through rigorous training and, out of 40, 10 were handpicked for the operation. Indian investigating agencies, FBI and Israeli Mossad are investing the case. In the mean time several people have come out on the street to protest the continual negligence of security threats by Indian intelligence agencies.

A Maharastrian Wedding

Talking about wireless all the time can be quite boring and doing it all day is definitely not happening. Decided to take a break, I went to my friend's wedding in Western Mumbai today.

My friend is a Maharastrian from Mumbai. Maharastra is a Western part of India situated along the coastline of the Arabian sea. India's demography is very diverse. Every state has its own autistic people and language. Sometimes I wonder how these states, widely apart in their identity, glue together and resonate harmoniously to one tune called India.

Nevertheless, ride to the wedding was effortless. I boarded a train from my place, got off at a station, piggy-backed in my colleague's car and headed for the wedding. We lost our way in the middle, but after series of queries with the the side walker and few U turns we reached our place. After diligently parking the car at a risky place we entered into the hotel.

First thing that took my breadth was the agility with which the wedding was pacing. Almost, within two hours of its inception, the wedding entered into its final stage: The Reception.

Maharstrian wedding is generally shorter, lasting only for hours, than the average duration of weddings in India. Strategically organised on weekends to force large attendance, it is constantly hammered with the unavailability of space and cost that sometimes justify its premature ending.

It starts off with Bride and Groom standing in front of each other. A long white cloth separates them. They hold garlands in their hands, made up of handpicked flowers, patiently waiting for the priest to complete his perennial chantings of rituals. Guests, in the meanwhile, shower the couple with the flowers occasionally digressing into their own animated conversations. When the priest finally finishes, the bride and groom exchange garlands and the wedding is complete. There is no time for "Saath Phare" which is quite common in Northern India.

After this the lunch party begins and begins a hustle to get a nice picture with the couple on the stage. The parents of both the party also stand with them. I also walked up to the stage and congratulated the newly weds. Then, after sharing some light moments with my Colleagues and Friends over there, it was the time for me to go back home.

802.16e Network Architecture

First, A question: Who do you think is responsible for IEEE 802.16e Network architecture development? IEEE? No! Ironic to the common belief, Wimax network architecture development is the task of Network Working Group (NWG) of Wimax Forum.

I will cover this topic briefly because I, myself, have a very limited knowledge of this topic. This topic is so vast in itself that it is almost impossible to cover it into one posting or in one Blog. So, I will give you some pointers in the end that will impart deeper knowledge of networking in the Wimax.

Wimax network is an all IP network, supports all usage model(fixed and mobility) and has a provision to support different Quality of Service(QOS). It has open interface for both within the Radio Access Network(RAN) and between the RAN and the core network. It supports all type of Voice, Data and Multimedia services.

Wimax Network, as shown above, consist of two important element: Network Service Provider(NSP) and Network Access Provider (NAP). NAP has two important elements: Base station and Access Network Gateway(ASN). Where as ASN gateways connects and manages different Base stations, NSP provides connectivity to different backhand networks(e.g. IMS). Wimax network supports both IPv4 and IPv6 protocols.

Multiple ASN profiles has been provided in the Wimax to manage diversity in ASN implementation and usage.There are three different ASN profiles(A,B,C) that depends upon the location of ASN and BS and also on the status of different interfaces (R1, R2...). Interfaces provides physical and logical connection between various network entities. They can be open(Vendor specific) or closed(NWG specified).

You can find more information about network architecture here

Okay, in the next blog we will be starting introductory Medium Access Control(MAC) of Wimax. Cheers!

Wimax Forum

From now on, we would be going into the depths of Wimax. But first, there is a good comparison of the existing wireless standards, I have displayed at the top of this blog. The wimax row is encircled in red. Notice that LTE is much much higher in throughput than the Wimax. Neways, we are not going to talk about the LTE here, we are loyal to wimax :)

Okay, today I will talk about the operating frequency bands of the mobile Wimax. I will also introduce the Wimax forum. It should be noted that the IEEE only makes the standard- It only talks about the PHY and MAC. What lies behind is specified by the the Wimax Forum. WiMAX Forum is a non profit organization formed to promote the adoption of WiMax compatible products and services. It is the job of the Wimax Forum to ensure interoperability among the devices from different vendors. Wimax Forum also dictates the band of operations, various PHY and MAC profiles to be included in the releases and over all architecture of the Wimax network. Those who passes the conformance and interoperability test can claim their product is "Wimax certified". Others adopt names like "WiMAX-ready", "WiMAX-compliant", or "pre-WiMAX", if they are not certified by the Wimax Forum.

Wimax Forum talks about the band of operation in terms of system profiles. Currently, only two system profiles are being certified: 1)2.4 - 2.6 Ghz 2)3.3 - 3.5 Ghz for the 10 Mhz band. I have also heard that the 700 Mhz profile is also being introduced, the auction for which has already been taken place in North America. The frequency plays a major role in the success of Wimax, as the range decreases rapidly with the increase in operating frequency, it will be good to operate at lower frequency in rural areas. I have a cellular phone which works in a 1800 Mhz band, and trust me I hardly get any signal inside my home. I have to go out to make a decent quality call. Products for both the profile are already available in the market. I will post a related document soon. In my next blog, I will talk about the network architecture and MAC layers of the Wimax.

Wimax Wifi Fight

There is a big misconception that Wimax is a replacement of Wifi. Perhaps, this doc will clear many misconceptions about Wimax. Click on the wimax myth buster under the heading wimax related stuff. Wimax and Wifi are completely different technologies with different goals. While Wifi is designed for the LAN (Local Area Network), Wimax has been engineered for MAN (Metropolitan Area Network). More simply, Wifi is for indoor and Wimax is for outside coverage.

Although underlying physical layer technology is same for both the cases (OFDM). It’s the MAC (medium access control) that differentiates between the two. MAC is needed to coordinate transmission between many to one situation. Wimax Mac is connection oriented. A logical connection is first established before data can flow through. This guarantees a minimal quality of service (QOS). We will talk about Wimax QOS later n our discussion.

Wifi is connection less and more contentious with its CSMA (Carrier Sense Multiple Access) Mac. In this type of MAC, a competing subscriber station (SS) listens to the channel, and when the channel is free, request for the transmission. Quite a different stuff altogether!

Wifi is also limited in range. Owing to free 2.4 GHz ISM band it operates in, wifi energy in the air is restricted to only couple of 100 meters. Where as Wimax works in a licenses band and can go up to ten's of kilometers.

In my next blog, I will be talking about the bands of operation of Wimax and Wimax forum.

Wimax: Part I Introduction

Hi there! I am sorry, extremely sorry. I had been crazy busy with the work I absolutely didn't get time to write. Nevertheless, as they say, better late than never. Let’s kick off and explore Wimax.

Wimax- Wireless Interoperability for Microwave Access. Purported as the last mile solution, this technology can deliver ubiquitous coverage in the range of 30 – 75 Mbps. But, before we go any further, we need to ask ourselves a simple question: why do we need Wimax? There are dearth of other wired and wireless technologies available, like: ADSL, Wifi, CDMA and GSM. So, why wimax?

If look at the statistics of wireless internet demand over the years, it should be pretty clear that, with the advent of multimedia rich mobile applications like you tube, web messenger etc, the demand for high speed internet is increasing exponentially.

Early usage of wireless internet was limited to e-mails and content browsing. But this is now changing very rapidly. We want to download music, watch videos, view content rich email attachments and do video conferencing. All these stuffs put tremendous burden on the existing wireless technologies that have very limited data rates.

But some may argue: we do have ASDL. Don’t we? Yes, we do have ADSL, but then is it possible to cover entire globe with wires? Don’t we feel liberated whenever we have a wireless substitute? The problem is more exaggerated in the case of developing countries, where the existing infrastructure is insufficient to support wired access to every one. So, in order to fill this huge gap of coverage and capacity, Wimax has been developed.

So, till I write my next blog, convince yourselves that we really need Wimax. I would be glad, if you invent some and write here based on your experience. In the next blog, I would be comparing Wimax with Wifi; An obvious comparison that comes in everybody’s mind.

Why max ?

Okay, I have figured out the contents of the wimax series. I will be covering all aspect of wimax, except handover (Coz haven't done it myself :)). In two months, I will tell you about:

1)Introduction (1 week)

2)Medium Access control (3 weeks)

3)Physical Layer (3 weeks)

4)Summary + Practical issues (1 weeks)

The focus will be more on practical than academics. I will not go into deep, but you are welcome to ask question pertaining to the discussion. For more clarity, I will be providing online consultancy in my off work hours through Bit wine consultancy. You can book a prior appointment. To know more about me visit peak2average.blogspot.com

Your comments are welcome!!

Coming Soon !

Starting from October 1, I will be writing an educative series on Wimax 802.16e. Covering Phy and Mac, you will get a comprehensive view of this exciting technology. You can also get your doubt (except IPR) solved through my Bitwine personal consultancy at a very nominal rate. I will be posting the link to which soon. So check my blog regularly !

Google's chrome

Monday morning, I was in the office, checking up my mail when I got a news update on the Goggle desktop. Google was unveiling it's new browser, christened, "Chrome" on Tuesday. So, was it an another great 'Google' secret? Huff! Anyways, I immediately fired my browser to the Google's homepage, filled with triumph, to be the first one at work to discover it. But my honeymoon got over soon, when I realized that it is Tuesday: by United States time.

Nevertheless, came the Wednesday morning, and while people are celebrating the Ganesh festival, I am here sitting and playing with this new Internet toy. First thing that I noticed about this browser is it refreshingly new interface. Layout is quite inviting, and the colors are apple for the eyes. Recently visited web pages greets you in an ingeniously placed square grid, when you open the browser. I found this feature quite cool, but a moment later not so cool :P (you know why right?)

Although, lots of innovation has been brought in with the chrome , but the one I like is the concept of "process" instead of threads. Google says that it optimizes the processing and does not render the browser freak out when a web page hangs. There is also a task manager, just like the windows task manager, that shows the memory and cpu consumption of a tab. This is quite useful because it helps to shut down a crazy, misbehaving website without murdering the browser itself. But still my browser crashed occasionally.

Downloading time was more or less same as compared to IE. I was actually surprised when I went to the Chrome downloading page, and found that the Chrome was only 446Kb. A smile bestowed on my face. But my belief in "There is nothing like free lunch" got strengthen, when I clicked on the installer.

I would strongly vouch for this new browser as a must have in every computer. I hope, google has also unveiled the linux version of chrome and if not, would do it soon.

Download it now here!

Opera mini 9.5 Beta

The other day when I read about opera mini, in some blog, I didn't know that I will find it so cool. I own a HTC touch, and I was frustrated with its IE explorer. I could not do blogging from my mobile. Can you believe this? So, while I was bitching about it to the CJ, I was also exploring the Mozilla Minimo (Mozilla web browser for pda and window mobile phone). Minimo made my touch go crazy. It frequently hanged with its monstrously heavy contents, and the interface was much similar to the FireFox itself.

But what drove me crazy was this new Opera Mini 9.5 Beta. HTC owners you got to have this in your phone. Its interface is so cool. It has tab browsing, feather touch movements and an amazing zoom in and out function. If you tap the screen twice the page in view would zoom in, and another double tap will zoom it out. I wish, I could show you :) It is also lightning fast. A new and improved compression technology has made the browsing two to three time faster. And with googles backing, this is surely a killer application.

Anyone agrees with me ?

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.

Lets get the G's right !!!

Telephone (from the Greek words tele (τηλέ) = far and phone (φωνή) = voice) ". When Alexander Grahm Bell in 1867 sent a trans Atlantic telegraph message, no one would have known that wireless telephony would travel such a long journey.

First, It was radio. Did you know that radio was used to pass on orders and communications between armies and navies on both sides in World War I?. Germany used radio communications for diplomatic messages once it discovered that its submarine cables had been tapped by the British. The United States passed on President Woodrow Wilson's Fourteen Points to Germany via radio during the war.

Radio is essentially an one way communication device (called simplex communication). After radio came the wireless walky talky. Walky talky is a half duplex communication device. In half duplex mode, since only one radio frequency is used, only one person can talk at a time. It was terrible way of communication with each conversation needed to end with an "over". So, It didn't last for too long. Nevertheless, it provided an effective mean to communicate messages across the places where it was difficult to reach by wire or by shouting. So, in a sense, Walky Talkies were the starting (I would call it 0G) of the true wireless communication. World didn't see the first version of commercial wireless telephone system until AMPS (Advance Mobile Phone System) was launched in the year 1983 (The year I was born :) ) by Bell labs in America. AMPS was first generation (1G) wireless telephone technology. It was toward the voice (analog signal) only . So no digital data were being transmitted at this point. Next, we will look at the Digital wireless telephony that is 2G, 3G , in my next blog

Hate the wire

Wireless has touched almost every one's life today. Be it your cell phone, laptop, wrist watch, they all have at least one inbuilt wireless module. Common vocabulary associated with wireless are wifi, bluetooth, 2G and 3G. While 3G is picking up lately, WiFi (Wireless Fidelity) hot spots are easily available at the airports, cafe, hotels and offices. I visited a cross cafe yesterday and was thrilled to find that I can surf Internet over wifi on my phone, while I smoke hukka. People are making their life easy with wireless. They can sync there PDA over the air with their laptops, transfer music, movies and ring tones between phones using bluetooth. In fact, I have seen people renouncing their good working phones and laptops just because it didn't have a bluetooth !! Today applications like You Tube, Orkut and Metacafe are heavily accessed on the mobile phones and hand held devices using the commercial cellular network. Isn't it great to have your favourite wikipedia on phone and you can access it where ever and when ever you want. It all has been possible because of wireless. Future belongs to wireless and it is necessary that we know it well. Wireless, essentially is a way to transmit information from one place to the other without using wires. Wires are clumsy, difficult to manage and sometimes hard to find! Mediums over which one can transfer information wirelessly are :
1) RF (Radio Frequency) It the most common medium you might be using everyday (cell phone, laptops)
2) IR (Infra Red) Your remote works on this (ever thought ? )
3) Laser Scantly used

Wireless also comes in many flavours with speed and distance distinguishing each other. In my next blog, I will be addressing this. I am also going to post some interesting link on this blog, which might be useful for you. So, start hating wires from today !!