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It seems that nothing can stop the runaway success of VoIP. Driven by increasingly widely available low cost broadband Internet telephony has become one of the fastest-growing applications on the World Wide Web. But apart from cheap calls in the UK, there are other factors which have contributed to this success story. There is clearly a trend toward more innovative and more mobile services and this looks likely to ensure that demand for Voice over IP continues to increase. It is estimated that there are already around four million VoIP Phone users in the UK, not counting business subscriptions.
People in the industry point to the advent of ADSL broadband connections that do not require line rental for a standard phone line (naked ADSL), and number portability between conventional and IP phone services as the two key factors that will bring increase the profile of VoIP to new levels.

In fact such has been the impact of VoIP that some have suggested that it may not be long before users can dispose of their traditional landline telephones completely in favour of a internet phone.

Taking a more practical view, there are issues that will need to be addressed before that can happen. In the UK Internet telephony providers like Vonage or VoIPTalk will have to scrutinise both security and ease of use, as well as continue to deliver a convenient and financially viable service. They certainly offer cheap calls already but, what else do they need to do to ensure a prosperous future for VoIP?
As the Internet is a huge public space the VoIP traffic is no more immune from attack than any other data. Security is an issue for many users, particularly in the business community and the means to develop security for users would be a welcome step in securing the long-term future of VoIP.

The ease of use issue may not remain a hindrance to progress now that handsets that work on mobile networks and, via WiFi or Bluetooth links, over VoIP are now making an appearance in the shops. This raises the prospect of using low-cost VoIP services at home, in the office or at a WiFi hotspot, but still retaining the flexibility of mobile coverage when out and about.

Some VoIP providers are now selling these handsets, and have set up joint arrangements with wireless hotspots so that their customers can make and receive calls on the go without the need for a computer.

Expect to see some of the restrictions of such handsets i.e. difficulties in hotspots that use web pages for authentication to be addressed any time now.

The advance of newer networking technologies will further minimise the gap between fixed, mobile and VoIP services. Wireless broadband services, in particular WiMax, could create city-wide wireless hotspots, making it possible to make mobile VoIP calls in much wider areas.

We looked at the Binary system, and basic computer logic elements, in previous articles, “It’s a binary world - how computers count” and “How computers add - a logical approach”.

Now we can combine two parts of these articles to look at a counter. Another common logic element in a computer is a counter or timer. This can b to count items going past a sensor on an assembly line, or possibly a count-down timer. For example, if you have a late model washing machine it will have a simple computer using a count down timer to give 10 minute wash cycle, etc.

There are several types of counter, nearly all of which use a basic element of electronics, the Flip-Flop. And you thought they were rubber shoes English people wear to the shower or the beach. (At this point Australians say “I thought they were called thongs”).

OK back on topic. The flip-flop is as old as electronics, and is a classic example of the binary system. It has two possible stable states, A or B, and can be ‘toggled’ from one state to the other, just like a ‘push-on, push-off’ switch. It was originally made with two vacuum tubes (or one, for example a double triode).

It normally has two outputs, one being the complement of the other. That is,if one output(A) is a logic 0, the other(B) is a logic 1, and vice-versa. The input, or Toggle(T) is at logic 0 until a pulse from a sensor, for example, comes along. This pulse takes the logic state to 1, then back to 0. The toggle effect, causing the Flip-Flop to flip, is actually the CHANGE from 0 to 1.

In logic terms the flip-flop is made up using AND and OR gates, in logic cicuitry it is just a ‘black box’ labelled FF. Several FFs may be grouped into yet another black box, a counter, timer, or multivibrator.

We can make up a Truth Table, which we have used before. If you recall, a truth table tells you what the Output will be for all possible Inputs.

TRUTH TABLE for Flip Flop - Toggle (C)hange,- Outputs A and B.

INITIAL STATE

T B A

0 1 0 ‘A’ output is 0

PULSE #1

T B A

C 0 1 ‘A’ output is 1

PULSE #2

T B A

C 1 0 ‘A’ output is 0

Now we string some flip-flops together to make a counter. Say we have a sensor on a beer bottling machine, which has to count 5 bottles before switching the feed, we need to count up to 5, or 101 in Binary. We will need 3 flip-flops, for binary bits 0,1 and 2, corresponding to decimal bit value of 1,2 and 4.

We will take the A output of the 3 flip-flops to a decoder black box, which we can use to detect when we get to 5, then switch the feed. The B output of flip-flop 0 is passed to the toggle input of flip-flop 1 via an AND gate, so the next pulse from the sensor (which goes to all 3 flip-flops) at this AND gate will toggle the flip-flop, depending on the value of the B output, 0 or 1. Similarly the B output of flip-flop 1 goes to the toggle of flip-flop 3 via an AND gate.

Our 3 Flip-Flops now come up with a truth table like this:-

INITIAL STATE

FF2 FF1 FF0

TBA TBA TBA

010 010 010 ‘A’ outputs 000 - 0

PULSE #1

FF2 FF1 FF0

TBA TBA TBA

C10 C10 C01 ‘A’ outputs 001 - 1

[The (C)hange flips FF0 (always). FF1 & FF2 are blocked by the AND gate which needs a 0 input from the previous FF 'B' output AND the pulse change.]

PULSE #2

FF2 FF1 FF0

TBA TBA TBA

C10 C01 C10 ‘A’ outputs 010 - 2

[The (C)hange flips FF0 (always). FF1 flips beacause the 'B' output from FF0 is a 0 when the Pulse arrives. FF2 is blocked as before.]

PULSE #3

FF2 FF1 FF0

TBA TBA TBA

C10 C01 C01 ‘A’ outputs 011 - 3

[FF0 flips, FF1 is blocked again,as is FF2.]

PULSE #4

FF2 FF1 FF0

TBA TBA TBA

C01 C10 C10 ‘A’ outputs 100 - 4

(FF0 flips, FF1 flips, FF2 flips.)

PULSE #5

FF2 FF1 FF0

TBA TBA TBA

C01 C10 C01 ‘A’ outputs 101 - 5 count complete!

[FF0 flips, FF1 and FF2 are blocked.]

This counter can count up to 111, 7 decimal, it then resets to 0. A couple of interesting points to note are:-

1. FF0 flips every pulse. FF1 flips every 2 pulses. FF2 flips every 4 pulses etc. These facts can be used to make up a divider, which can be cascaded. For example the 4 pulse output can go to a second counter which also gives a 4 pulse output, totalling 16. This can be expanded to make up a decadic counter by decoding a count of 1010 (10 decimal) and using this to toggle the next counter, etc. What about 60 and 12 for your digital watch?

2. Look at the ‘B’ outputs from the counter. In sequence the values are:- 111, 110, 101, 100, 011, 010 (7,6,5,4,3,2 decimal). See the pattern? That’s right - a countdown timer! We’ll be using this in a later article.

Tony is an experienced computer engineer. He is currently webmaster and contributer to http://www.what-why-wisdom.com. A set of diagrams accompanying these articles may be seen at http://www.what-why-wisdom.com/history-of-the-computer-0.html.

Do all of us really require a laptop computer? It sure seems that way because demand is soaring. I worry that like last year we will have issues getting the latest technology too. Laptops have been a thriving industry year on year for a number of years now and it looks like that will continue. Also with portables now it looks like every 6 months or so the technology is already taken over with something new.

With all the latest progress in technology gaming laptops have capitalised a great deal in my opinion. I think gaming laptops have never been at such low prices. You can find some really good bargains out there that will get you gaming. I play games on my laptop on a frequent basis and must say I’m surprised how playable some of the intense games are. I also think that some gaming laptops look really smooth, with some slick, aggressive features. Ok so there remains a difference in power no matter how advanced gaming laptops have become but that should always exist. It looks as if everybody is obsessed with designing slimmer, lighter notebooks and I’m certain we will see gaming laptops like that soon.

I think demand for custom notebooks will always be about. The notion of aquiring after market components entices some people in my opinion. By being able to negate some add on’s from the spec you can truly save cash on components you won’t use. Pre-configured laptop computers are targeted at people who have common needs and that is probably not you right? So hence this is why you require a custom notebook computer. There are plenty of small laptop assembelers about that provide amazing customer care. Because of this consumers will give up on the large brand name.

I think a lot of geeks are awiting the next wave of notebooks. One subject I haven’t spoken off is the evolution of low priced ultramobiles. new market has been made suddenly it looks. These days consumers desire slim notebook computers but they additionally desire massive lcd’s. This is a thing that can be achieved even now if we forget about performance. Laptops for playing games on will get sleeker, that’s for certain. Laptop computers come out every few months and these low priced portables possibly made a number of companies change their ideas.

For the performance these are the best laptop computers.

Broadband is ultra fast speed internet access, and is noticeably speedier than snail pace dial-up access over a modem. If you are viewing this internet guide then you are maybe looking at buying internet access for the 1st time, or thinking to increase your internet speed to broadband.

The main advantage of high speed internet access is you are able to listen to music over the net, all this has became astonishingly popular with the BBC launching their new player which will allow users to see the most current shows of Cheers. With high speed internet access users might also get dance music & Hollywood movies at a much greater speed than dial-up access.

High speed internet access is effortless to hook up. The 1 st step people will need to do is register with an ISP, of course known as an Internet Service Provider, and they will supply users with a high speed connection through your home line. If surfers already have a broadband supplier then make sure surfers try a broadband comparison online website for neutral guidance on the finest deals. People may quickly note the finest deals with an internet provider comparison service by just putting in your street name & then the service will give a list of high speed internet packages in your area. Browsers will be under no pressure to sign up with any provider while surfers look through the provider deals. Compare broadband packages and deals with a comparison site.

Once people have signed up with your ISP the internet corporation will often arrange a day for turning on the connection and supply people with any required hardware & internet software. The wireless routers & broadband software can often come with step by step guides & most internet corporations will offer customers IT advice if needed.

Once you have successfully connected to the worldwide web people might well start to adore the super fast speeds of broadband. If surfers are going to download music, telly shows such as Location Location Location or hollywood movies please be aware of any download limits users may have on your www package. Classical music and telly downloads such as X Files could take up most of your ‘download allocation’ as the broadband company are huge in file size.