Microwave Internet

[sbk]

I am currently visiting the family in the US and my sister has microwave internet. Wow is it fast! I am sure there is nothing like that available on Koh Phangan but was wondering if they have it in Thailand at all? It costs something like $40/month and this was the bandwidth test:

Communications 2 megabits per second

Storage 248.8 kilobytes per second

1MB file download 4.1 seconds

Smokin!

So, why isn't it available in Thailand? It doesn't require any wires so it seems like it would be quite practical for some places.

[Simmo]

So, why isn't it available in Thailand? It doesn't require any wires so it seems like it would be quite practical for some places.

I did some work with microwave links between offices back in aus.

Some of the cons are:

Needs a large infrastructure of base stations. Line of sight required between base station and aerial. High latency , short distance and prone to dropouts in bad weather depending on frequency used. Regulatory issues with the typical frequencies used.

[Tywais]

Simmo is correct on all points. In the US the infrastructure has already been in place for years. Microwave transmitters/repeaters have been around since the 50s and was how CATV (cable TV) sent their signals between sub-stations so it was a relatively easy transition to add networking to it. Thailand has no such wide spread infrastructure for this and other technologies would be better if starting from scratch.

Range: 20 miles, typically less

Line of sight only, point to point

Rain causes problems, because rain absorbs microwave energy

[sbk]

Thanks for the explanation. They live in Colorado, high desert. it doesn't rain much here. I wondered if it might be expensive to set up, but couldn't figure out why it was so reasonably priced then!

I am enjoying it, I can tell you!

[SMS]

Thanks for the explanation. They live in Colorado, high desert. it doesn't rain much here. I wondered if it might be expensive to set up, but couldn't figure out why it was so reasonably priced then!

I am enjoying it, I can tell you!

What kind of reciever do they have? some antenna/router at the home which you gotta plug into your computer or something more portable? I can only imagine being able to move around in a 20 mile raduis surfing

Its all about economics... The number of people who have the connection.

Here in thailand they(TOT) were (or still are not sure) testing/considering WIMAX to provide internet and telepone to rural areas. Each base station has a raduis of about 50 KM and costs in millions of bahts. And again rain/wether is the enemy.

[astral]

Do not be fooled into thinking that microwave means speed.

It is all down to what the ISP can/will offer.

I have a 128K wireless link here in a coastal area of the Middle East and it costs me $50 a month.

Expensive, yes, but there is no ADSL in my area yet, rolling out this year, but then I will need a phone line as well.

I do get a real 128k. I monitor it with DUMeter.

Very heavy rain will cause drop out, but not very often and we have had some pretty heavy storms here during the winter.

Technical difficulties are more likely to be the reason for loss of service.

[meadish_sweetball]

Simmo is correct on all points. In the US the infrastructure has already been in place for years. Microwave transmitters/repeaters have been around since the 50s and was how CATV (cable TV) sent their signals between sub-stations so it was a relatively easy transition to add networking to it. Thailand has no such wide spread infrastructure for this and other technologies would be better if starting from scratch.

Range: 20 miles, typically less

Line of sight only, point to point

Rain causes problems, because rain absorbs microwave energy

Which technologies would be better for Thailand, do you think?

And does anybody have a clear picture of what the Thai ISPs are developing and planning for the coming years?

[Tywais]

Which technologies would be better for Thailand, do you think?

And does anybody have a clear picture of what the Thai ISPs are developing and planning for the coming years?

SMS's mention of WIMAX I think is a suitable technology. It is still considered microwave due to the frequencies used but has some techniques to not require line of site in certain circumstances. However the important thing is that it may not be necessary to build microwave towers or repeaters and can be potentially used within the cellular tower systems (shared) that are in place now. Repeaters may still be needed for more remote regions. Of course the beauracy of the governing agencies in Thailand (you know who you are) could make that quite a challenge.

"Even in areas without preexisting physical cable or telephone networks, WiMAX could allow access between anyone within range of each other. Home units the size of a paperback book that provide both phone and network connection points are already available and easy to install."

Good reading here: WiMax - Wiki

[Prasert]

Rain should degrade the signal in theory.

But the funny thing is that I'm connected at this moment to the internet from my house up the hills, and this connection uses a microwave link over about 1.5km to the village.

Signal strength at the moment (storm and heavy rain): -66dB

Signal strength during a sunny day (or dry night): -67dB

Beats me........there's hardly any difference, anyway not enough to degrade the connection!

Edited May 19, 2006 by Prasert

[monty]

There is one very little published disadvantage on wimax, and that is that it can seriously degrade reception of satellite signals...

Wimax is on 3.66Ghz I think, where c-band satellite goes from 3.625 till 4 GHhz.

This might blanket out a lot of the weaker c-band signals for those people watching television through their own dish...

Don't forget the wimax transmitter will be a couple of miles away, the satellite transmitter is about 36ooo km away!

[Tywais]

Rain should degrade the signal in theory.

But the funny thing is that I'm connected at this moment to the internet from my house up the hills, and this connection uses a microwave link over about 1.5km to the village.

Signal strength at the moment (storm and heavy rain): -66dB

Signal strength during a sunny day (or dry night): -67dB

Beats me........there's hardly any difference, anyway not enough to degrade the connection!

Generally, rain attenuation increases as the signal frequency increases. Therefore, transmissions at 6/4 GHz (C-band) will experience insignificant attenuation, while transmissions at 14/12 GHz (Ku-Band example: UBC - why UBC drops out so easily in light rain) will experience greater attenuation. For 6/4 GHz signals to be affected would require rain storms approaching hurricane conditions. Signals at higher frequencies can be affected by less severe storms. So it all depends on the microwave frequency they are using.

C band is primarily used for satellite communications, normally downlink 3.7 – 4.2 GHz, uplink 5.9 – 6.4 GHz, usually via twenty-four 36MHz-wide transponders on board a satellite. Most C band satellites serving North America use linear polarization, while most of those serving other continents (particularly Intelsat satellites) use circular polarization. The 802.11a wireless networking standard operates in the 5GHz area, and some recent-model cordless telephones use frequencies in the 5.8GHz vicinity

[Prasert]

The attenuation on higher frequencies is correct, but it's beyond the allowed frequencies in Thailand.

802.11b/g (2.4GHz) can be used without license as long as the EIRP stays below 20dBm. 802.11a (5GHz) is not allowed in Thailand, and the same story goes for WiMax (3.6Ghz).

Satellite links are basically receive-only (TV) so the frequency is not an issue. However when you use them to transmit as well (eg IPstar), the usage of the frequency will require a license.

So when you want to use microwave links to get internet connectivity on remote locations, the choices are limited down by the regulations of the government.

By the way: Thailand uses the same regulations for 802.11b/g as the rest of the world.

[Prasert]

I am currently visiting the family in the US and my sister has microwave internet. Wow is it fast! I am sure there is nothing like that available on Koh Phangan but was wondering if they have it in Thailand at all? It costs something like $40/month and this was the bandwidth test:

Communications 2 megabits per second

Storage 248.8 kilobytes per second

1MB file download 4.1 seconds

Smokin!

So, why isn't it available in Thailand? It doesn't require any wires so it seems like it would be quite practical for some places.

When you come back to Thailand, visit the island north of yours. I'll show you that these links are being used in Thailand!

[monty]

Prasert, are the links on Koh Tao privately (e.g. ISP) or government (TOT, CAT,...)?

What is the technology?

Basically making a multiple kilometer wireless bridge is not hard, even using of the shelf 802.11b/g parts... You'll only gonna breach the 20dBm EIRP limit...

I had a 3.5 km link like this, was getting the full 11mbps with decent SNR as well...

[astral]

This is the diamond shaped antenna that was installed on the roof of my apartment block

for Wireless Internet. The frequency is somewhere around 3Ghz I was told, so there

is no interference with Ku Band tv antenna.

There is a small box attached, a modem I assume, and then a LAN cable down to my apartment.

Edited May 21, 2006 by astral

[Prasert]

Prasert, are the links on Koh Tao privately (e.g. ISP) or government (TOT, CAT,...)?

What is the technology?

Basically making a multiple kilometer wireless bridge is not hard, even using of the shelf 802.11b/g parts... You'll only gonna breach the 20dBm EIRP limit...

I had a 3.5 km link like this, was getting the full 11mbps with decent SNR as well...

The links are from my company, I installed them myself. And the 20dBm limit is not breached, since both antennas on each side of the link are very sensitive. When you do a proper calculation on the power of the radio, the loss in the coaxial cable and the gain from the antenna, it's easy to stay below the legal limit and cover a big distance.

Technology: Cisco 802.11g radio, AircomPlus coaxial cable, a parabolic antenna on one end and an omnidirectional antenna down in the village.

[monty]

And the very high sensitivity of the cisco radio helps a lot...

Very hard to do with the cheaper stuff though...

[tabalatsointsoin]

There is one very little published disadvantage on wimax, and that is that it can seriously degrade reception of satellite signals...

Wimax is on 3.66Ghz I think, where c-band satellite goes from 3.625 till 4 GHhz.

This might blanket out a lot of the weaker c-band signals for those people watching television through their own dish...

Don't forget the wimax transmitter will be a couple of miles away, the satellite transmitter is about 36ooo km away!

WiMAX is available at various frequencies: 3.5, 2.3, 2.5 GHz... In order to avoid interferences with satellites.

[thohts]

1 mb in 4 seconds isn't really that fast.

At my Bangkok hotel, I can download 1 mb in about 6 seconds.

Granted, I'm sure fast connections are quite expensive here.

I thought about a satellite connection when I was too far out for an ADSL line, but could only find http://www.thaicom.net

Edited May 22, 2006 by thohts