In part one of this series (“Implementing satellite-based Internet access”), I explained that using satellite-based communications for Internet access is a good alternative to dial-up Internet access if you live in an area in which broadband Internet access is unavailable. I covered some of the issues you need to consider before implementing satellite-based Internet communications that you wouldn’t encounter with terrestrial-based connection methods. Finally, I began showing you how to locate the satellite in the sky. In this Daily Drill Down, I’ll finish showing you how to locate the satellite’s position in the sky so that you can make sure you’ve got a clear line of sight. I’ll then go on to explain the pros and cons of the services of two leading satellite-based Internet service providers (ISPs).
Establishing a clear line of sight
In “Implementing satellite-based Internet access,” I showed you how to calculate the compass heading that you’d have to point the dish toward in order to receive a signal. However, your satellite must also be aimed at the correct vertical angle (typically referred to as elevation) before you can get a signal. Determining the correct vertical angle is a little trickier than finding the compass heading.
Unless someone provides you with information regarding the correct angle, you probably won’t be able to calculate the exact angle, but you can usually get close enough that you can tell if there will be a clear line of sight. To do so, you have to know your approximate position on the earth, based on latitude. Once you know this information and the fact that the satellite will be located about 22,000 miles directly above the equator, you can draw a triangle to measure the approximate angle. Remember that triangles are made of straight lines, but the earth is curved. Therefore, you’ll have to draw one of the triangle lines below ground. Keep in mind that when measuring the angle, you’ll have to measure it from ground level rather than from the triangle line that runs below ground. You can see an example of such a calculation in Figure A. If you have trouble performing such a calculation, just consider this: I’m in South Carolina and my elevation angle is around 44 degrees. Therefore, if you’re further north than I am, the angle will be smaller, and if you’re south of me, the angle will be bigger.
|Calculating the elevation angle isn’t always easy.|
Once you’ve calculated the approximate elevation of the satellite, it’s time to see if you have a clear line of sight. To do so, go outdoors with a compass and look at the compass heading that you calculated in part one. Now, look into the sky at the angle that you just calculated. I used a device that’s used to measure the altitude of model rockets (see Figure B). You can pick one up at a hobby shop for under $20. If you have trouble finding one, you can easily make your own by tying a weighted string to the center of a protractor. As you look along the edge of the protractor, the string will tell you the angle that you’re looking at.
|You can use a device such as this to look at the correct position in the sky.|
The first time I measured for a satellite dish at my new home, I found that I had a big tree between myself and the correct location in the sky. If this happens to you, there are a few things you can do about it. The satellite is so far away that moving to a different horizontal or vertical position within your yard won’t change the angles that you’ll have to use. Therefore, if there’s a big tree in the way, you can always move to the left or right of it or move the satellite dish vertically by attaching it to your roof or putting it on a flagpole. (Just make sure to ground it properly so that it won’t become a lightning hazard.) As you can see in Figure C, the dish’s vertical position can make all the difference in the world as to whether or not you have a clear line of sight.
|The satellite dish’s vertical position makes a difference in whether or not you have a clear line of sight.|
So far, I’ve told you everything you need to know about how satellite-based Internet access works and how to figure out if it will work for you. Now, let’s take a look at two of the more affordable satellite-based ISPs, StarBand and DirecPC. It’s important to point out that I’m not endorsing either provider or recommending one service above the other. I’m simply presenting the facts about each service provider as they were on May 5, 2001.
DirecPC offers the type of satellite-based Internet access that I described in part one. The DirecPC system uses a satellite dish for downstream communications (communications from the Internet to you) but relies on a phone line for upstream communications (things that you send out to the Internet). So what does this mean for you? It means that downloads will be fast (comparatively speaking) at up to 400 Kbps, but uploads will be limited to your modem’s capabilities. It also means that depending on where you live, you may have to have a standard ISP in addition to the DirecPC service. In some areas, DirecPC offers its own phone line-based Internet service for about $10 per month.
Because of the way the DirecPC service works, it requires special software. You won’t be able to simply use the standard dial-up networking components that are normally associated with Internet communications. The current version of the DirecPC software is version 3.0. DirecPC 3.0 supports the use of either a USB-based satellite modem or a PCI card satellite modem. The USB version works with Windows 2000, Windows Me, Windows 98, and Windows 98 SE. Windows 95 isn’t supported.
If you’d rather use the PCI-based satellite modem, then you have a few more choices in operating systems. Windows 2000, Windows Me, Windows 98, and Windows 98 SE are all still supported. You can also use Windows 95 and Windows NT (with Service Pack 3 or higher).
Regardless of which type of satellite modem you’re using, the minimum hardware requirements are a 200 MHz or faster CPU, 800x600 video resolution, a 28.8-Kbps modem, a CD-ROM drive, and 20 MB of free hard disk space. The memory requirements depend on your operating system. The minimum RAM requirements are 128 MB for Windows 2000 and 64 MB for the other operating systems. Of course, software doesn’t always run well with the minimum hardware requirements. I recommend that you use higher-end hardware if possible, such as a 400-MHz processor and a 56-Kbps modem.
DirecPC’s price really depends on the type of service you get. Rates vary based on whether you use their ISP for dial-up access or use your own. The rates also vary depending on whether you want unlimited Internet access or a few hours per month. Here are just a few of the current prices. You can get all of the details at the DirecPC Web site.
- 25 hours per month without ISP: $19.99 per month
- 25 hours per month with ISP: $29.99 per month
- Unlimited access without ISP: $39.99 per month
- Unlimited access with ISP: $49.99 per month
If you choose one of the rate plans that only include 25 hours per month, then additional time is either $0.99 per minute if you use your own ISP or $1.99 per hour if you use DirecPC’s ISP service.
Of course, if you intend to implement satellite-based Internet access, you’ll also have the cost of the satellite dish and receiver (modem). There are several different types of receivers available; they range in price from $150 for a basic model to about $700 for one with all the bells and whistles.
Another alternative for home-based Internet access is StarBand. StarBand offers two-way Internet access through the satellite. This means that you won’t have to resort to tying up a phone line when you want to access the Web. The StarBand service functions similarly to a DSL or cable modem in that it’s always on. You never have to dial in to a service provider. The StarBand service offers maximum download speeds of 500 Kbps with an average speed during peak usage times of over 150 Kbps. As you can see, like with a cable modem, the available bandwidth is shared among the various users. Upstream communication speeds typically range between 40 and 60 Kbps.
Buying a StarBand receiver is a little bit different from buying a DirecPC receiver. Like DirecPC, you can use either a USB-based satellite modem or a PCI card-based satellite modem. Unfortunately, the only way to get the PCI version is to buy a new PC from Radio Shack that has the card included. You can, however, buy a USB satellite modem directly from StarBand and use the USB modem with an existing PC.
If you do intend to use an existing PC, the minimum hardware requirements are a Pentium-class processor with 32 MB of RAM and 120 MB of free hard disk space. You’ll also need a CD-ROM drive and a free USB port. Of course, if you don’t have a free USB port, you can always use a USB hub to gain additional ports.
The StarBand software will run on Windows 2000, Windows Me, Windows 98, and Windows 98 SE. Because of the USB port requirements, Windows 95 and Windows NT aren’t supported.
So what about costs? If you end up going with the USB version, you can order a StarBand receiver online for about $400. StarBand also requires professional installation, which runs about $200. Throw in another 40 bucks for taxes, and a StarBand system will set you back about $640. The StarBand subscription fee is $69.99 per month for unlimited access.
Internet connection sharing
One of my main concerns in selecting a satellite-based Internet service was the ability to service multiple PCs. I was particularly concerned about this ability since StarBand and DirecPC both use proprietary software. However, I’m happy to say that both services can be shared to multiple PCs through the use of Internet connection sharing or through a proxy server.
So which is better?
As I said at the beginning of this Daily Drill Down, I’m not making any recommendations, just reporting the facts. In a nutshell, StarBand offers higher performance and tends to be more convenient since it doesn’t require a phone line. That performance and convenience comes at a price, though. If you’re on a budget, consider DirecPC.