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Analysis: The next great Net connection

SunWorld

(IDG) -- I have had DSL in my home office for about 18 months now, and I've decided to ditch it. Why, you ask? Am I having too many connection problems? Does my ISP have uplink bandwidth issues? Are my networked computers responding badly to the DSL modem?

Actually, none of that. My always-on DSL connection has gone down about three times: once when a blackout powered down the Cisco 675 modem and twice when my ISP was upgrading its network equipment and the Cisco 3810 that my line connects to. I've also had a fairly steady 768 Kbps bidirectional stream. It certainly is worthwhile for those 1 GB downloads I have to do occasionally for reviews.

One major security risk with the Cisco 67x series DSL router is that the encryption for your security password is simply a one-letter transposition (i.e., c translates to b), making it totally worthless securitywise. However, I use mine as a bridge, so it isn't really possible to telnet or connect to the device directly except through a physical serial line.

My ISP's lines aren't the fastest (several T1s), but that hasn't caused me any major trouble. My computers don't mind the DSL modem either, except that as a bridge the link has to constantly send 43-byte ATM cells every three seconds or so to the virtual router at the other end, causing constant periodic traffic on an idle LAN.

So what's my beef? Money and power. Actually, the cost of the DSL service and the traffic speed that I get. US West charges about $80 per month in my area for a 786 Kbps symmetric DSL line. On top of that, my ISP is charging about $250 per month for the Internet service. That may sound reasonable to a regular business (which I am), but most home users would rather not pay as much. Except for those living in major cities on the east and west coasts, most people have to pay exorbitant prices for high-speed network services. That doesn't bode well for future Internet and Digital TV services.

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Luckily, a friend of mine introduced me to a new Sprint service currently being tested in the Phoenix and Tucson, Ariz., market for possible deployment in cities nationwide. Imagine getting 2 Mbps downlink and about 100-200 Kbps uplink for your home for a measly $40 per month. That is 3,200 percent faster than a 56 Kbps dialup modem for about twice the price of a common analog dialup modem service.

It is 267 percent faster than my 786 Kbps symmetric DSL, but it includes both the physical link and the Internet service all in one. That's about $250 less than what I'd pay for a slower line. I won't be getting a 786 Kbps uplink as I did with my DSL connection, but like most people, I download more than I upload anyway.

To give you a comparison, the three-hour, 15-minute-long movie Titanic, in full digital video, can be downloaded in about 30 minutes, using Sprint Broadband, about one hour and 40 minutes over 786 Kbps DSL, and about 30 hours with a 56 Kbps analog modem. It is still not quite enough to send a full HDTV signal through (about 19 Mbps) but you could receive an Internet video stream at 640 by 480 pixels at about 30-40 frames per second, which is close to your TV set's quality.

Unfortunately, Sprint's service does not always give a level 2 Mbps, and there are often latency issues in the initial connection to a site after the wireless network has been idle for a while. That is separate from the DNS lookup procedures, which take additional time. Furthermore, for service in Tucson, Sprint's network actually takes my packets all the way to New York and back down to Tucson to reach my old account, which is connected to Global Crossing. That last factor depends on where you are going on the Internet.

Broadband wise

Sprint Broadband is a multimegabit asymmetric service that works over Multichannel Multipoint Distribution System (MMDS) fixed wireless. It uses the reserved frequency ranges at 2.1 GHz and 2.5 through 2.7 GHz that at one time were reserved for television signals. That can now be used for any kind of two-way digital communication, and it is separate from the 2.4 GHz bandwidth commonly used in microwaves, portable phones, Bluetooth wireless devices, IEEE 802.11b Wireless LAN, and other wireless equipment for the home and office. That means that microwaving a burrito while you make a phone call at home won't suddenly degrade your Internet connection to a crawl. That frequency is also used for wireless cable. It shares some of the same problems with cable Internet services, which is no surprise since the Tucson service was once a wireless cable TV company that was later bought by Sprint.

It is a fixed wireless system, which means you can't use it for your laptops or PDAs unless you plan to walk around with a 15-foot pole and align the connection each time yourself. The whole process takes a few hours to mount properly. Marcos and Faith, the professional installers who set up my link have set up temporary locations for conventions and shows to demonstrate the system's flexibility.

Sprint Broadband is a shared medium whereby all customers are transmitting and receiving from the same antennas, so the more users, the lower the bandwidth for each person. However, in a nonbusy network, I can get data rates of 3.2 Mbps down and about 500 Kbps up. A friend who introduced me to the service gets 2 Mbps regularly, and an acquaintance even claims to get the maximum per customer of 5 Mbps down. Sprint only guarantees a maximum of 2 Mbps due to the variance in quality dependent on the customer's location. Each modem can handle a theoretical maximum of 30 Mbps down and 10 Mbps up, but Sprint does not yet offer such a high rate. In addition, according to my Sprint installation crew, each customer antenna can support up to 200 cable modems.

Sprint's technology is based on towers covering a 35-mile radius cell, which in the case of Tucson includes almost the whole city and some outlying areas. The antennas communicate within fixed blocks of frequency ranges assigned to an area or sector of the city. The modems also use an address mechanism conceptually similar to a MAC or Ethernet address for distinguishing between traffic intended for home antennas and for others within the area.

The asymmetry is due to the size and power of the transmitting antennas at the customer's location. Those transmit data on a smaller frequency range, so less actual data bandwidth is going up to the main towers for that particular area. You could have faster uplinks, but you would need more powerful antennas at your location, and Sprint would have to allocate a larger frequency range to you. From the provider's point of view, that isn't economical because most customers typically have a large discrepancy between how much they download and how little they upload.

Installing the service

The actual antenna is a small quadrangular flat dish that looks like a mini traffic sign. Mounting the antenna on the roof of a home works in one of two ways: you can have the antenna mounted on a pole beside the house that stands over the height of your roof, or you can have a platform set up on the rooftop for the antenna to stand on. Either way is structurally sound when professionally mounted, so your choice would depend on your house's design and personal preference. You would also need to get permission from the landlord, building manager, leasing company, or realty company before mounting the antennas, and heed any neighborhood or zoning restrictions.

Tucson and Phoenix are particularly appropriate because of those cities' largely flat terrain and surrounding mountain ranges on which towers can be set up to serve large areas. However, a problem called the Multipath problem occurs when a location is too close to the mountain range and just below the general beam of the dish, or it overlaps between two sectors or cells. In such a case, you may not be able to get the service despite its proximity. Although the technology can work through trees and other see-through obstructions, the quality of the signal rapidly declines, so you still need a clear line of sight to the tower.

The coaxial line (same RG-6 as used for cable TV) runs inside your house and into a cable modem. The modem can then connect directly to a PC or a 10BaseT Ethernet hub to a network. Sprint configured the cable modem onsite in a few minutes and handed me address information. To test it out, we set up one Win98 machine to request a DHCP (Dynamic Host Configuration Protocol) address from the network, and I was ready to go.

Sprint will normally demarcate their responsibility at your PC that is hooked up to the modem. However, if you have a LAN, you can ask them to demarcate at the modem instead. That means that Sprint Broadband technical support will only help you troubleshoot the connection and the attached devices up to the demarcation point. For nontechnical home users, you should go with what they say and let them demarcate at the PC.

Sprint Broadband doesn't allow the customer to run a proxy server or NAT (Network Address Translation) to share one valid public IP address against a number of computers. That is to discourage customers from filling up the shared bandwidth. You can have multiple computers for the Personal service for an extra $10 per month per address. The Business service starts with five IP addresses and costs $10 per month for additional ones.

The addresses are dynamically assigned DHCP addresses, so if you have several addresses, your machines will get one IP from a block reserved for your network. You can also statically assign those addresses to each machine. From a provisioning standpoint, its simpler to allow a customer to set their Windows or Macs to dynamically accept the machine rather than remember the address numbers, DNS addresses, gateway, and subnet mask. The true geeks will probably prefer to do it by hand.

Coming to your city

The new service might seem wonderful, but will it be available near you? Possibly. There are two companies in Tucson that offer that kind of fixed wireless service at high data rates, and Tucson isn't that big. Deployment of the service is dependent upon the city's geography.

Sprint will next be testing in San Francisco, Denver, Detroit, and Silicon Valley. According to Robert Hoskins, director of marketing, the company plans to expand its broadband wireless offering to 15 other cities by the end of 2000 and to another 50 by the end of 2001, mostly west of the Mississippi. Other large carriers and ISPs that are looking into bringing out MMDS are MCI/Worldcomm in the northwest and BellSouth in the south and the east coast.

Deploying such a service at an affordable rate is well worth it for the mass market. Once homes and communities have higher-speed network connections, the Internet can grow. Instead of a matchbook-size video image, we can get a more reasonable picture. Other services will eventually develop as higher speed becomes possible.

At the same time, if not planned properly, we might see a significant increase in traffic problems on the Net. All those newly laid fiber and 10 Gbps links at the core of major ISPs may be swallowed up before they deploy fully. But that should be a worry for the top-tier ISPs.

To my own selfish end, I'm going the American way and hurrahing for the competition that has brought that affordable and fast service to my neck of the ... errr ... desert.




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