Low cost
Available on a BT land line
High Speed Connection.
No need for web space
Unlimited download rate
No need for helpdesk
The tiscali package matches all of my needs and is the cheapest out of all the providers listed that offer unlimited usage. The connection I would need is an ADSL modem which is provided free of charge from tiscali. The speed is 512k which is sufficiently fast for my home use needs which would include internet browsing, downloading media and online gaming. I do not have the need for any web space as I do not run a website or want to share any files over the internet. I am prepared to pay for any help needed as I have sufficient knowledge to troubleshoot problems myself and I estimate that any use of the helpline would be minimal. The package also includes multiple email accounts which I need for myself and family.
2.1 Internet connections
The 4 main methods of establishing an internet connection are through the use of and ISDN line, High speed modem over the PSTN, Cable Modem and ADSL technology, each of the 4 will be described in more detail below.
ISDN Line.
ISDN, which stands for Integrated Services Digital Network, is a system of digital telephone connections which have been available for over ten years. This way of connecting the internet allows both data and voice to be transmitted simultaneously across the connection using digital connectivity at each end of the transmition.
ISDN works through transmitting data through different channels called bearer channels. Each channel has a data rate of 64kb/s, although this can be regulated via the service provider, and the speed is limited to 56kbp/s through a telephone. This is the maximum data rate a standard telephone can handle due to the frequency that the line operates at.
One detail that users must take into consideration when looking at ISDN speeds if that the use of the term kbp/s when describing the speed is that with ISDN k is equal to 1000 bytes where as with all other internet connections the use of the term k refers to 1024 bytes.
Most ISDN service providers use dual channels, by combining the two you can achieve higher data rates than that which could be achieved via a dialup modem, also with ISDN the connection is constantly on and the end user does not have dial up the connection.
The computers at each end of the link use an industry standard protocol which allows them to understand each other, the protocol is called TCP/IP this stands for Transmition Control Protocol and Internet Protocol, The TCP part of the protocol dictates when the data is sent and that data has been received by using positive acknowledgement and the IP part controls where the data is going by using and IP address.
ISDN lines need an external modem to enable connectivity.
The highest data rate that can be offered via a dual ISDN connection is 2 x 56k which is 128kbp/s. This is the common method of connection although you can combine more than two connections to get even higher data rates
The cost of operating this type of connection for a year would be £192 with installation costs on average costing £50
High speed modem over the PSTN
This uses a basic dial up modem over the Public Switch Telephone Network (PSTN). Out of all the connection methods this is the slowest as it uses analogue signals over the copper telephone line connected to you house. With a dial up modem you cannot use the telephone line when you are connected to the internet. As the connection speed is so slow the computers at each end of the connection compress the data before it is sent and the computer receiving the data then decompresses it at the other end, this enable a higher data rate to be achieved.
These types of modem can be both internal and external, where the internal type connects in to the computers PCI card slots and the external type are commonly connected via the computers serial port or newer version are connected via the computers USB port.
This dial up method also uses the same TCP/IP protocol as ISDN and the maximum data rates that can be achieved through this method is 56kbp/s.
The running costs of this type of connection for a year would be on average £180 per year with no installation cost, the only cost at outset may be the purchase of a modem which are available from £15
ADSL Technology.
ADSL stand for Asymmetric Digital Subscriber Line. This again uses your home telephone line, but it requires your telephone line provider to change it to cope with the requirements of ADSL. ADSL work by using higher bandwidth on your telephone line. Where a normal telephone line uses a set frequency to transmit voice data, and ADSL enabled line uses a much greater band of frequency allowing more data to be sent. This can interfere with a normal telephone call and therefore you need a micro filter in your telephone line before your telephone, these cuts out the ADSL frequency and provide the standard telephone frequency.
To use ADSL you need an ADSL modem, this converts the data being sent down the telephone line and coverts it into data to be sent to the computer. The modem can be connected either via a USB port or though an Ethernet port in the pc depending on what ports are available on the pc being used.
Currently ADSL speeds are increasing all the time, currently the maximum ADSL speed available is 4mbp/s
The running cost for a year on average would cost £240 with setup costs usually costing nothing with the supplier offering free installation and modem.
Cable Modem Technology
The term Cable Modem is relatively new and refers to a modem that operates over the ordinary cable TV network cables. Basically you just connect the Cable Modem to the TV outlet for your cable TV, and the cable TV operator connects a Cable Modem Termination System (CMTS) in there end (the Head-End). The term Cable Modem is a slightly misleading, as a Cable Modem works more like a Local Area Network (LAN) interface than as a modem.
The Majority of ISP providers using cable modem technology supply external cable modems. The external Cable Modem is the small external box that connects to your computer normally through an ordinary Ethernet connection.
Another interface for external Cable Modems is USB, which has the advantage of installing much faster (something that matters, because the cable operators are normally sending technicians out to install each and every Cable Modem). The downside is that you can only connect one PC to a USB based Cable Modem. This is very much like an ADSL Modem.
Cable Modems are much faster. Speeds from x25 to x1000 are possible today compared to a standard dial up modem, and we are now only at the beginning of the Cable Modem era! Cable Modems are on-line whenever you turn on your computer. Just like the network (LAN) used in most offices etc.
Errors that can occur while using these types of modem are usually down to poor cables being used which can corrupt data being sent down the line. Also if the incorrect protocols are used then the two computers will not be able to communicate.
Again a cable modem used TCP/IP technology as all the other types of connection do. Currently the maximum speeds that ISP’s offer for this type of connection is 3mbp/s although speed of the link is actually more like 1gbp/s ISP’s currently limit the speed of the link due to the costs of running at higher speeds.
The running cost for a year on average would cost £240 with setup costs usually costing nothing with the supplier offering free installation and modem.
2.2 Conclusion for best use.
Out of the four connection types available the one most suitable for my own personal use would be the ADSL connection type. I would choose this type due the high rates of data transfer it offers and the affordable cost of running the connection. Installation costs are usually free and installation is usually very easy with it being implemented myself with my telephone provider enabling the telephone for ADSL use
3.1 Appendix
3.2 Bibliography
(Cable Modems.org) 10/03/2005
(Webopedia) 15/03/2005
(ADSL Guide) 15/03/2005
(Broadband Reports.com) 23/03/2005
(ISDN Tutorial) 24/03/2005