The single facet of over-the-road driving that has continually driven me to distraction is the inconvenience and high cost of maintaining an open and easy line of communication with friends and family; not to mention business contacts. Even using a cell phone, though highly convenient, can be quite costly. That's why, from the first time I realized that it might be possible to make cheap (or even free) phone calls from the truck stops I frequent, I've been fascinated with Voice over Internet Protocol (VoIP).
Just a few years ago VoIP, which routes calls over broadband Internet connections instead of traditional phone lines, was employed exclusively by a small band of geeks talking to each other using complex software and cheesy microphones. Skype and Vonage have succeeded in bringing VoIP to the masses by simplifying the software and introducing user-friendly hardware. Now, truck stops offering Wi-Fi hotspots have made it possible for truckers to take advantage of VoIP services, as well.
So...How Does VoIP Work?
Through the use of a coder-decoder, more commonly called a codec, analog audio signals are converted into compressed digital form for transmission via the Internet; and then back into an uncompressed audio signal for replay. In order to convert an audio signal into thousands of digital packets suitable for transmission over the Internet the codec, of which there are many, employs a technique known as "Sampling" in which small samples of the signal are taken several thousand times per second. The number of samples will vary, depending on the codec used, and range between 8,000 and 64,000 samples per second. Each sample is converted into digitized data, compressed for Internet transmission, and, when the thousands of tiny samples are reassembled, it sounds like one continuous second of audio signal.
And Why is VoIP so Cheap?
The answer to this is fairly simple and can best be explained by example. If you make a call via the traditional Public Switched Telephone Network (PSTN) a circuit is created between you and the person you're calling, for the duration of the call. This is why a PSTN is referred to as "Circuit Switched". Your voice is digitized (using a codec) and, along with thousands of other voices, combined onto a single fiber optic cable. The myriad voices are transmitted at a rate of 64 kbps in each direction for a total dedicated bandwidth load of 128 kbps per call. Since there are 8 kilobits (Kb) in a kilobyte (KB), this equates to a bandwidth usage of 16 KB each second the circuit is open. In a 10-minute conversation, the total transmission bandwidth used is 9600 KB or, approximately, 10 megabytes.
The Internet, however, doesn't need to use circuit switching. In fact, the Internet is based on the concept of "Packet Switching". Meaning that little packets of data flow freely along thousands of possible paths; each packet containing not only the pertinent data but all the information needed for reassembly into the correct order. Additionally, packet switched data networks send and retrieve only as needed so no constantly open circuit is necessary. Combining codec driven data compression with the efficiency of packet switched networks result in a total bandwidth use of between 3 and 16 kbps; as opposed to 128kbps.
As you can see, VoIP is far more efficient than the Public Switched Telephone Network. That efficiency translates into lower cost. Some services, providing both parties are using the same service and the calls are PC-to-PC, charge absolutely nothing. That's right, they cost zip, zilch, nada. Now THAT's what I'm TALKIN' about!
Issues With VoIP at the Truck Stop
Even though its highly unlikely that cell phones will be replaced by VoIP phones any time soon; VoIP is being used by an ever growing number of truckers. But there are problems - and one of the problems facing drivers desiring to save on long-distance bills by using VoIP is the fact that many truck stop hotspots connect to the Internet via satellite. Because communication satellites are located in geostationary orbit more than 22,000 miles above the earth's equator, it takes time for the signal travel up from the truck stop to the satellite and back down to the relay station where the hard wired connection to the Internet is made. This delay, known as "latency", has little effect on most Internet related activities but it wreaks havoc on voice communications.
Another issue facing those of us hoping to make use of VoIP at a hotspot is the differences in upload and download speed. Most Internet related activities, like web surfing and checking email, make greater demands on the download side than the upload side so Internet connections, whether satellite or hard-wired, are typically configured to provide higher download speeds. This bandwidth differential can cause problems when you're attempting to use a truck stop hotspot for VoIP calls because the alloted upload bandwidth might not be sufficient. While I've made entirely enjoyable VoIP calls with an upload speed of less than 200kbps, sometimes far less, I've found that upload speeds of 300kbps are about the minimum for ensuring high-quality connections.
At any truck stop hotspot, you can run a simple bandwidth test using a service like Speakeasy to see the download and upload speed. For the most part, as long as the location isn't too busy, you can get a good idea of the bandwidth available. Another testing option, more VoIP specific, is to visit a site like TestYourVoIP.com or VoipReview.org where you can get a fairly accurate idea of whether or not the current connection conditions will support VoIP calls. These sites measure the upload and download speeds but they also measure Quality of Service (QoS) issues like bandwidth jitter and packet dropping.
Because more and more of us are using VoIP services some hotspot operators are optimizing their networks to provide better quality calls. Chances are good, though, that truck stops will be amomg the last to incorporate QoS (Quality of Service) technology, which adds priority to video and voice streaming over wireless networks. Hotspots that do use QoS will prioritize VoIP calls over web page or email downloads because connection problems are more obvious with VoIP.
VoIP Service Providers
VoIP providers fall into three basic categories:
- Phone-to-Phone: An ATA (analog telephone adaptor) allows you to connect a standard phone to your computer or your Internet connection for use with VoIP. Providers like Vonage and AT&T CallVantage are among those whose focus is primarily on the home and business users. Vonage does offer at least one option, however, that might be of interest to truckers: the Vonage V-Phone. Another interesting contender, with an entirely different twist, is Jajah.
- PC-to-PC: While many of the more popular services started life limiting VoIP calls made PC-to-PC only; most of them have evolved to include PC-to-Phone service as well. There are still a few notable exceptions including a new VoIP service offered by Flying J called eValue Talk.
The eValue Talk service is currently in Beta, meaning the final version is yet to be released, and calls are limited to PC-to-PC only VoIP calls. If you have an annual or monthly Wi-Fi subscription the service is free. Since eValue Talk is still in Beta I'm not sure whether or not it will remain PC-to-PC only or whether the call list will remain limited to two; not including the subscriber. - PC-to-PC or PC-to-Phone: There are more providers falling into this category than I can possibly hope to list. If I say the top five are Skype, Yahoo! Messenger, AIM Phoneline, Google Talk and MSN Messenger I'm sure to be harangued by those in love with some other VoIP provider so - I won't say they're the top five - they're just the first five that come to mind.
