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Showing posts with label Wireless. Show all posts
Showing posts with label Wireless. Show all posts

Slow Internet!

One of my friend asked to me once, “What are the two things you don’t like about computers?” I said, “A slow computer and a slow internet connection, they really piss me off”. And the latter seems to be ‘stalking’ me all the times, no matter where I go or what technologically advanced the ISPs are.
Back when it all started, there was only one speed available - 56Kbps - the dial up. At that time, I didn’t have any choice but to wait hours and hours for a page to load, sometimes even to get connected. Even the internet cafĂ©’s offered dialup or sometimes ISDN, which was not much better.
Then came the cable. The first cable connection I used had a speed of 64Kbps. It wasn’t much better either. But the best part was the fact that it was unlimited. I read somewhere that broadband means both high-speed and seamless connectivity. The cable belonged more to the ‘seamless connectivity’ category (Don’t get confused, there were lot of outages also, but as compared to the speed, there was connectivity most of the times). Still there was one problem – the download limit. I never was a cable subscriber myself, but I really hated (and still do) the idea of putting a download limit on the connection. It’s like giving something you like and telling don’t use it. (This is applicable only to power users I guess)
Fed up by all this, I promised myself that if I am ever going to take an internet connection, I’ll get the one with max speed with no download limit. That day came when I moved to Bangalore. I subscribed the 256Kbps Home ULplus plan from BSNL, which was the max speed unlimited connection offered at that time. (Most of my readers are familiar with the story of getting that one). When they came up with the 512Kbps plan, I immediately switched to it. But it doesn’t matter what speed they offered in their ads, always the speed was intermittent. I had no choice but stay with the same connection as there were no other providers in that area. I felt jealous about my friends who had Airtel connections because of their stability. They gave a constant speed (at least when I used them). Whenever I heard about the stories of connections abroad (from my friends), I wanted to experience it myself. Then again I reminded myself, I am still in India, and lucky to have a decent internet connection.
Then I moved here. And one thing I was very optimistic was that I will be able to browse as much as I want with the broadband link speed not being a bottleneck. I was proved wrong the first day itself since the place I stayed had a wireless (3G based) internet. It was worse than the one I used to have in Bangalore. I couldn’t stand it, the next week itself, I subscribed a new 3Mbps unlimited broadband (ADSL) from Singtel. They said that the first week will be a bit rough as the traffic has to adjust and some crap. But as they said, after one week, I started getting steady high speed internet. I really enjoyed using it. The internet speed never became a bottleneck for any of my normal routines. I thought that the bad days are over.
But that thought didn’t last long. For last one month, I am continuously calling my service provider’s customer care centre about the intermittent connection. I have a 3Mbps connection and sometimes it even takes up to 30+ minutes to download a 1MB file (based on the speed test suggested by the customer care executive). Sometimes I have to wait for long times even to load the google.com. Think about that. It’s not consistently slow also. And guess what, a technician came last week and did something (what he did, he didn’t reveal) and for 3 days the connection was fine. Again I have to start calling the customer care. As things currently stand, there is another technician’s visit planned for the coming weekend.
Its really pissing me off. Is it so hard to provide a consistent broadband connection? I am also familiar with the data networking and related fields and based on what I know, if you have the right equipment and if they are under the correct permitted load, it’s not that difficult to provide a good link. It’s not that they are doing a charity but I am paying the internet bills promptly every month. What would they say if I started paying the bills intermittently? I wonder sometimes, Is it just me or is every broadband consumer faces similar experiences?

Steps to take a BSNL Broadband connection in Bangalore - Final Part - My Diwali Gift

...Assuming you have read the first and second part of this one which is available in my blog archive...
10 Oct 2007, Wednesday
After getting my phone activated, I called the JTO. He told me, the process for broadband will automatically be started after my landline gets activated. After that, it may take around 10-15 days to get the connection. I also asked whether there is any modem shortage or so, but he said, there is no shortage.

22 Oct 2007, Monday
It is exactly 2 weeks since I got my phone line and still no word of the broadband. I called the JTO. After trying till evening, I finally got the call connected. He checked with my phone number and told me, the broadband is now in the process of creating username. When I asked how much time it will take for that, he said may be 1 week or more, it is done in another section. [I wonder how complicated it is to make a username]. He also gave me the number of that ‘section’. I called, called and called. Nothing happened except the phone ringing, ringing and ringing.

23 Oct 2007, Tuesday
I went to the place where I gave the application. They directed me to the exchange. [They were very friendly to me] First they told me there is some software updates going on and it will take only 2-3 days. Then they checked with my landline number and said that I will get my connection with in November second week for sure. Once again I got assurance for another 2-3 weeks.

3 Nov 2007, Saturday
I was at this shopping mall and its then that I got this call. He introduced him as calling from BSNL and whether he can come on Monday to give me the connection. I couldn’t believe it at first. For me getting the BSNL connection was like attaining a long lost dream or something like that. I immediately agreed and told him to call me before he comes. He said he will come in the afternoon.

5 Nov 2007, Monday
I waited till 3pm. I thought again I missed it. Then I called the JTO in my area and asked about it. He gave me the number of another guy and told me that the one who called me was on leave that day. I called the new one and he said he will come soon. And by 4:30pm he called me saying he will come soon. I went home from office. And finally he came. He gave us the wireless router itself, the one we applied for. I asked him whether they had the stock and it seems like they’ve just got the new stock. He did all the configurations. But it was not yet the actual connection. He said it will take 2-3days more to activate it in the exchange. Atleast we got all the hardware and configured them and are fully ready for the net. He gave me the username, the password and the helpline number too.
I have to admit one thing. Even if the BSNL are slow, the people working there (from my experience) are all very friendly and are always there to help. I am talking about the people, a customer will come in contact with. On November 9th, I will celebrate 2nd month anniversary after giving the application.

8 Nov 2007, Wednesday [Diwali]
I got a Diwali gift, not from my friends or relatives, but from BSNL. Yeah! I got my broadband connection. I don’t know how they managed it, but they activated it precisely on the Diwali day and manage not to test my patience by extending it to a third month. They gave the connection precisely on the 2nd month itself. Even now, there are some more problems, but I hope they will be solved in due time. Nyway, thanks BSNL for the Diwali gift and for letting me complete this trilogy about the pursuit of me for the broadband connection.

802.11n - The NeXt Generation Wireless Standard

From my first blog, you may know that I have joined another firm recently. Here, I will be working in the same domain as my earlier one - IEEE 802.11 a.k.a Wi-Fi or Wireless LAN [WLAN], my personal favorite. Now that I am having some free time at my new firm since my joining formalities are not finished, I thought I will spend some time researching the new trends in wireless domain. It is then that I came across a commercial claiming a data rate of around 300Mbps for a wireless product. But the products which I worked in, 802.11g compliant, will provide a maximum of 54Mbps (raw data speed) only. I had some idea about 802.11n, but I never thought they will provide this much speed. And thus, I thought I’ll spend some of my time researching about 802.11n.

A word of caution before I go in to the details: I am assuming the reader of this blog is familiar with IEEE 802.11 basics, not in the user perspective, but in a developer one since this contains technical stuff unlike my other blogs. Non-technical people, skip to the summary section.

Setting the new standard
As I said, the wireless product I previously worked had a maximum data rate of 54Mbps. It was an 802.11g certified product. In the 802.11 base spec (1999), three PHY layers were defined, an FHSS (Frequency-Hopping spread spectrum), a DSSS (Direct Sequence Spread Spectrum), both in the 2.4GHz band and an Infrared PHY which is obsolete now. Then released were the 802.11b (DSSS) (July 1999) which supports 11Mbps, 802.11a (OFDM – Orthogonal Frequency Division Multiplexing) (July 1999), which supports the 54Mbps raw data rate. But 11a didn’t get in to that wide acceptance because of the very fact that it operated in the 5GHz spectrum. Then the 11g came with 54Mbps data rate which operated in 2.4GHz spectrum and is used by almost all the Wi-Fi certified products now. In the case of 802.11n, the draft specifies many ‘options’, like many configurations and we can make it work in any possible configurations. With every possible options turned on, you will get a raw data rate up to 600Mbps. (Data taken from
http://www.broadcom.com/docs/WLAN/802_11n-WP100-R.pdf) I will give a comparative table to show the details rather than explaining.
As you can see from the table, 11n has a very high data rate compared to others. But that is the raw data speed with the entire data rate options turned on. From the user level perspective, you will get around 100-200Mbps. Even that is a great boost from the conventional 802.11ga mode.

802.11n specific features
One of the great features of 11n is the use of multiple antennas which is known as MIMO - Multiple Input Multiple Output. Basically it uses more than one antenna to send the data packets in multiple streams. It exploits the phenomenon called multipath, which usually is treated as interference in radio communications. Two important benefits of MIMO are antenna diversity and time-space multiplexing. The draft specifies antenna configuration option of up to 4x4. This feature can be a power consuming one and so the draft n specifies a power save mode also. So the multiple antenna configurations are used only when maximum throughput and data rate is required.
Other options in the 11n specification are,

  • Better OFDM - The OFDM in 11n is improved so that the maximum data rate which can be achieved is 65Mbps rather than 54Mbps in 11g.
  • Wider channels – 11n provides options for 40MHz channels instead of the conventional 20MHz ones. But the downside is that the number of channels will be less and so it doesn’t give much space for other devices to transmit in the same airspace.
  • Reduced Inter-frame Spacing [RIFS] - A smaller inter-frame spacing than that of 11a or g which uses the SIFS [Short IFS], PIFS [PCF IFS], DIFS [DCF IFS]& EIFS [Extended IFS]
  • Aggregation - This feature is used in the case of inter-operability between the legacy modes 11b/g and 11n. It uses transmission burst in between the overhead communication there by improving the efficiency.
  • Greenfield Mode - This is an optional mode which allows an all 11n network which doesn’t have to give any backward compatibility with the 11b/g devices.

These are some of the options which can be turned on and off. So by fine tuning them, you can attain really high data rates as compared to the present 11g devices.

Summary
Just going through the table above itself, we can see that the 802.11n will surely bring a revolution in the wireless domain in the case of both data rates and range. But only at the cost of MAC/PHY layer becoming more complex. The applications of 802.11n will become prominent in VoIP (Voice over IP), streaming video and music, gaming, NAS (Network Attached Storage) etc. Already there are around 70 products in the market which are 802.11n Draft 2.0 certified. The 11n standard is supposed to be ratified by fall 2007 or early 2008.

References

ps: If you come across any discrepancies, please do comment on it.