The Model Info Center

Having made calls using VoIP without issue for for ages I was baffled as to why out of nowhere I had been having lots of issues. Sound quality has reduced and latency issues have become markedly noticeable. Users on VoIP online forums in the US and other countries, such as France and Mexico, have been noting similar issues since last year. For a while Voice over IP might seem like a good deal for the average person, more established interests in the telecoms industry see it differently - and are doing something about it.

Consultation

Well aware of what has happened elsewhere the United Kingdom telecoms regulator Ofcom took the unusual step in February of announcing that it will look at the growing VoIP industry and report next month on whether new laws are necessary to protect it. The consultation document says: “VoIP service providers have expressed concern that their ability to provide a reliable service may be impacted by internet access providers (ISPs) selectively degrading or blocking their VoIP traffic.”

Ofcom says it has no evidence this is happening in the UK; only about 000 customers use it. But the prediction is for that to go up by 4m in the next six months.

And VoIP barring takes place in other countries, more often than not those where there is still only a single incumbent telecoms company. In Saudi Arabia, for instance national carrier Saudi Telecom is using software from US supplier Narus to block all Voice over IP phone calls.

Telcos in the United States as well as other countries are hesitant to have their bandwidth used by traffic from which they earn no revenue and have been challenged over similar alleged incidents of VoIP blocking. Barring VoIP traffic is a challenge but not illegal and barring precise kinds of internet traffic is going up.

The European based VoIP giant Skype who are now owned by the pre-eminent auction site eBay has been particularly controversial. Skype is used by over 75m people. But not everyone wants Skype on their network.

Skype is considered by a lot of people to pose a potential security threat because it creates an encrypted channel out of the network and forms supernodes that sit on it and set up VoIP calls. There is big debate about how much bandwidth such supernodes eat up. There have been claims that in supernode mode, Skype could possibly saturate a 100 Mbps line.

Compared to some of the more successful products by Nokia the 1112 is boring. Nokia have done a good job on the functional design of this mobile phone. With the 1112 Nokia have produced a mobile handset which is functional, if a little basic for a entry level mobile handset.

If you want a fantastic deal, buy online where it is simple to find many really cheap deals to select from. It is simple to find the best offers on a Nokia 1112 try using a mobile phone comparison site to compare mobile deals .

The 1112 supports 2G GSM 850 / 1900 - US version . Regarding the all important battery cell duration the Nokia 1112 has 5:00 talk time and 380 hrs standby time. A Standard battery, Li-Ion 700 mAh (BL-5CA) battery is that comes with the Nokia 1112. The 1112 has Polyphonic (20 channels), with MP3 grade tones ring tones enabled plus a vibrating alert . The Nokia 1112 weighs only 80 g. If colour is something you are interested in you may like to know that the 1112 can be bought in, Red, Blue and Black. Compared to other models, the 1112 is small and comfortable to carry. The screen is a Monochrome graphic. There are also a number of additional features included with the Nokia 1112 such as , Exchangeable covers, Picture messaging, Built-in handsfree, Reminders, Speaking alarm and clock and Demo mode for phone.

This is now quite an old handset, but still does a great job. If you are offered one, being cleared as old stock you can grab a great buy.

GPS, or Global Positioning System, is the latest thing in keeping from getting lost when trekking out to visit your Aunt Louise. Years ago you had to rely on landmarks, your handy compass or the guy at the corner gas station, assuming he knew where everything was. Today for about a hundred bucks you can get a little gadget that will tell you exactly where you are, any place on Earth. By using some basic mathematical calculations and a rather complex system, you can be in the middle of the desert, lost as can be, push a button and have your GPS tell you exactly where you are so that you can hopefully find your way back home.

So what exactly is GPS and how does it work?

GPS is actually a very complex and expensive system but the fundamental concepts of the system are very simple.

The GPS system is a group of 27 Earth orbiting satellites. Twenty-four of them are in operation and 3 are backups in case one fails. The system was originally created for the US military but was eventually opened up to everyone else.

Each one of these satellites, weighing in at about 4,000 pounds, circles the Earth at about 12,000 miles per hour and makes 2 complete rotations everyday. The orbits are arranged so that at any one point in the day 4 of these satellites are visible from any place on Earth.

The complimenting receiver that was created to receive signals from these satellites has the job of locating 4 or more of these satellites, figure out the distance to each and from that information determine where on the planet the receiver itself is located. It then transmits this location back to the person who happens to be in possession of the receiver. The operation is based on a simple mathematical principal called trilateration. To simply explain how this works, let’s say someone tells you that you are 10 miles from Newark, NJ, another person tells you that you are 15 miles from Maplewood, NJ and a third person tells you that you are 20 miles from Woodbridge, NJ. By taking those three facts you can figure out exactly where you are because each radius of each distance when linked together will intersect at only one point. That point is where you are located.

In order to actually do the calculation from space the GPS receiver needs to know 2 things. The location of at least 3 satellites above you and the distance between you and each of those satellites. The reason that only 3 satellites or spheres are needed is because the Earth itself can act as a fourth sphere. The GPS receiver itself works by radio waves which are a kind of electromagnetic energy and travel at the speed of light The receiver can actually figure out how far the signal has travelled by timing how long it took for the signal to arrive from each of the satellites.

In the next article on GPS we’ll go over exactly how this system works to measure distance.

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Michael Russell
Your Independent guide to Global Positioning Systems
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