Search Engines

By: Gary McManus
The best thing about the Internet is that there are oodles of pages out there referencing all sorts of information. Unfortunately the worst thing about the Internet is that there are oodles of pages out there referencing all sorts of information. So how do I retrieve the information I need? Answer: Search Engines.
In the following series of articles I will endeavor to explain the concept of search engines and their use, both for retrieval and submission of information.
What is a Search Engine?
A search engine is a system that contains a coordinated set of programs that allow users to enter a search request and return a list of pages that reference this request. These programs include:
* A spider program that goes to every page on every Web site that wants to be searchable and reads it
* A program that creates an index (catalogue) from all the pages that have been read by the spider program
* A program that receives your search request, compares it to the entries in its search index, and returns resulting references to you
There are two primary methods of searching, keyword and concept. The most common method is keyword, with concept offering more of a challenge to search engine companies.
Keyword based systems perform their text query using retrieval of keywords. The web page developer can specify words for indexing, or the search engine, using a predefined method (e.g. first 20 lines) indexes the pages. Most search engines these days will index every word on every page, whereas others will index only certain parts of a page. These indexes can be built up using a subset data on the page (e.g. title, headings and subheadings, links or the first ‘x’ words in the document).
Concept based systems try to determine what you mean as opposed to what you say. These systems return references to documents that are ‘about’ the search request as opposed to exactly what you specified. Using this method, words are examined in relation to other words found nearby on the page. These methods use sophisticated linguistic and artificial intelligence theories to perform the search (too complicated to start explaining here). When certain words and phrases occur close together in a document the system concludes by statistical analysis that the document is ‘about’ a certain topic.
In the next article I will explain how to maximise the use of search engines, and retrieve pages most appropriate to your search area.
The TSSG recommends using Google ( for keyword searches (it also has a downloadable taskbar for Microsoft’s Internet Explorer which allows you to search at any time without having to go to the Google home page first, see For browsing through broad categories of information the TSSG would currently recommend using Yahoo! (either for the World, or for the UK and Ireland). Interestingly, Yahoo! actually uses Google for their own keyword searches!

Convergence of Telecommunications and Inter Networks

By: Mary Nolan
Converge is the title of a project being run by TSSG to investigate the above issue. Since their initial development over thirty years ago, computer communications systems, particularly the Internet, have been designed independently of Public Switched Telecommunications Networks (PSTN). These systems have sometimes interacted, particularly in the use of the PSTN to carry Internet traffic, but attempts have just recently begun to really converge the services provided onto a single integrated network architecture.
These convergence attempts have been motivated by the fact that one of the key requirements in deploying a pervasive and ubiquitous information superhighway is the development of a global integrated telecommunications infrastructure. This global communication network will have to deal with a wide spectrum of traffic characteristics, because the network will have to support, simultaneously, applications that have a wide range of expectations and requirements.
The reasons for the fundamentally different designs of the PSTN and computer networks are several. The PSTN was developed to carry telephone calls, whereas the Internet and other computer networks were intended to transfer asynchronous data between computing devices. Telephony has strict quality of service (QoS) constraints – the user will not tolerate significant time delay, variation in this delay (jitter), loss of communication or unavailability of service.
By contrast, computer communications services have not had such stringent time constraints. Delays of the order of seconds have been considered acceptable. Access to a computer network has generally been with sophisticated devices that are capable of recovering from data loss in the network (i.e. requesting resend of packets, etc). Thus a “best-effort” communications service was considered sufficient.
The different evolutionary paths and different levels of quality of service guarantee have resulted in fundamentally different approaches to charging for the use of these two networks. PSTN users primarily pay for usage on the basis of time and distance, since a fixed portion of a limited resource is guaranteed to the user for the duration of a call (to provide quality of service). By contrast it is unreasonable to ask users to pay for usage of best-effort Internet services where no guarantees of quality of service can be made. Thus, payment for computer communications services has generally been on a monthly flat-rate basis (any time-based charges are just for access over the public telecoms network).
Three major aspects of this convergence are being investigated:
* Quality of Service – mechanisms for delivery of telecoms services over the Internet with sufficient quality guarantees.
* Accounting – pricing of future quality Internet services (while maintaining revenue streams for telecoms companies); systems are required to account for usage and charge correctly.
* Security – granting users access to services (i.e. authorisation); authentication of users (so the correct user is billed); enhancement of privacy of user communications and integrity accounting data gathered.

Concerns about Electronic-Commerce

By: Mary Nolan
Electronic-Commerce otherwise referred to as E-Commerce is defined by Kalakota & Whinston (1997) as:
“The delivery of information/products/ services/payments over phone lines, computer nets & other electronic means”
Products have been available for purchase by telephone for a number of years, a consumer provides credit card details, which are then verified by a teller and the consumer can then place an order, product types could range from saucepans to concert tickets. This method of purchase has proved popular as it is still in use today.
However with the evolution of the Internet, more products and services have become available on-line. This to the consumer should mean a more convenient way of purchasing various goods and services, as there are no more queues for tellers. However significant issues such as security are now emerging. Companies want tools that allow them to know with some certainty that customers are who they claim to be so that billing can be charged against the proper accounts. Similarly, consumers are concerned about the security and privacy of on-line transactions. They want to know that only authorised eyes will see personal account information or credit card numbers. Several dozen companies are working on extensions to Internet protocols to provide these types of security features.
When we make a purchase by telephone we are reasonably assured that our information is safe. However making an on-line purchase is slightly different. A purchase order with consumer’s details is filled in analogous to a consumer filling out an order form and sending it in a paper envelope via postal mail. The consumer is reasonably certain that the order and credit-card
number will arrive safely, as any tampering with the envelope will be blatantly obvious. However Internet mail finds a route to its destination without knowing the identity of each node it passes through and any evidence of tampering is not as evident, this is tempting to unscrupulous individuals.
To defray these risks, many on-line businesses use various security protocols. One in particular is SET, Secure Electronic Transactions protocol. This is an open encryption (used to scramble a message and make it unreadable to intermediate nodes on its route) and security specification designed to protect credit card transactions on the Internet. SET is not itself a payment system. Rather it is a set of security protocols and formats that enables users to employ the existing credit card payment infrastructure on an open network, such as the Internet, in a secure fashion. With the use of Digital Certificates, used to identify each party involved in the transaction, both consumer and company can be sure they are dealing with the correct person.
With the development and improvement of these protocols purchasing on-line will become as much a part of our daily lives as getting out of bed in the morning.

An I on Things To Come

By: Keith Hearne
Many people will have heard of the acronym WAP (Wireless Application Protocol) in connection with wireless devices especially mobile phones. However, not so many will have heard of i-Mode but are probably guaranteed to sometime soon.
First introduced in Japan in February 1999 by NTT DoCoMo, i-mode is one of the world’s most successful services offering wireless web browsing and e-mail from mobile phones. Whereas until recently, mobile phones were used mostly for making and receiving voice calls, i-mode phones allow users also to use their handsets to access various information services and communicate via email. When using i-mode services, you do not pay for the time you are connected to a website or service, communications fees are charged by the amount of data transmitted/received rather than the amount of time online. That means that you can stay connected to a single website for hours without paying anything, as long as no data is transmitted. As with WAP phones, i-Mode phones use a microbrowser to view specially marked up pages (WAP pages are in WML, i-Mode pages in cHTML or compactHTML). However when comparing these two services you must remember that WAP is a protocol, while I-mode, now japans biggest internet access platform, is a complete wireless internet service, presently covering almost all of Japan with over 13 million subscribers.
Japan’s i-Mode offers more affordable access rates, more robust content, and higher connection speed. Services available let users send and receive email, exchange photographs, do online shopping and banking, reserve tickets, find a good restaurant, download personalized ringing melodies for their phones, access the internet directly and navigate among more than 7,000 specially formatted Web sites.
The whole i-Mode experience when compared with WAP is much easier for users. When retrieving web content, before accessing a site WAP users must agree to pay extra charges and even type in URLs to browse through sites other than the service provider’s portal. i-Mode phones have a one-button browsing method, eliminating the need to type in Web addresses.
Currently, i-Mode accounts for over 60 percent of the world’s mobile Internet users, and 99.9 percent of these users are Japanese, but this will soon change. DoCoMo is currently bringing i-mode to the United Kingdom and Europe, and has already started using an English version in Japan for foreigners. This means it’s time to dust off your Kanji and hop on the i-mode bus. So keep an I on the shape of things to come.

Internet Protocol Version 6 – Evolution or Revolution?

By: John Ronan

If you have Internet access, you use IPv4 every time you connect to the Internet, every time you send an email or every time you look at a web page. IPv4, Internet Protocol version 4 or just plain IP, is the protocol or set of rules for communication, which is used today on the Internet.
IPv4 was designed a long time ago in computer terms (about 1980) and since its inception, there were many requests for enhanced capabilities. Currently IPv4 serves what could be called the computer market, the driving force behind the growth of the Internet.
However, as nomadic personal computing devices seem set to become ubiquitous with their prices dropping and their capabilities increasing, it seems likely that the next phase of growth will probably not be driven by the computer market. Replacing the current generation of mobile phones, pagers, and personal digital assistants (PDAs), these types of devices will need to communicate with the current generation of computers and the new Internet protocol will need to support this.
With the advance of digital high definition television comes the possibility that every television set will become an Internet host, blurring the difference between a computer and a television and adding another functionality requirement to the Internet protocol.
It’s also possible that the next generation Internet protocol could be applied to controlling devices. This consists of the control of everyday devices such as lighting equipment, heating and cooling equipment, motors, and other types of equipment currently controlled via analog switches and in aggregate consuming considerable amounts of electrical power. The size of this market is enormous and requires solutions, which are simple, robust, easy to use, and very low cost. The potential pay-back is that networked control of devices will result in substantial cost savings.
IPv6 is a new protocol, intended to supersede IPv4 and it has been the proposed standard since November 1994. IPv5 is already reserved for another protocol, which never really made it to the public, hence IPv6. As a natural increment to IPv4, IPv6 is designed to be the evolutionary step forward to provide a platform for the new Internet functionality that will be required in the near future.
The challenge was to pick a protocol that meets today’s requirements and also matches the requirements of emerging markets such as the ones we have described. These markets will happen with or without IPv6 but if IPv6 is a good match for them it is likely to be used. If not, then the market leaders will develop their own protocol.
Due to the size and scale of the new markets, it is also probable that they will each develop their own protocols anyway, perhaps proprietary. If this happens then these new protocols would not interoperate with each other i.e. your phone could not talk to your fridge, or your DVD player/recorder and the opportunity to create an immense, interoperable, world-wide information structure with open protocols would be lost.
The alternative is a world of disjointed networks with protocols controlled by individual vendors.

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