1. DSL
Basically, in beginning, the cheapest service of Internet was given to the common users through PSTN dial-up. This service is still available. It allows user to access Internet simply by dialing a phone call to telephone operator through connection manager in system. After connecting and authenticating, telephone operator connects that PC to ISP through telephone line and gives the service of Internet. These analog telephone signals demodulated by dial-up modem in user’s PC. The major disadvantage of this service is that the signals are sent by ISP to users through a ‘phone call’ which occupies full bandwidth which is basically set up of voice. This bandwidth is at the most 56 kbps. Considering today’s needs, 56 kbps is not enough even for images. Also, the telephone line remains busy during the Internet connection is on. Hence, in order to overcome this disadvantage, a Broadband technology called as ‘DSL’ (Digital Subscriber Line) was developed. With use of this technology, the regular public switched telephone line can be set up for Broadband. This procedure is very economical and does not cost much because it uses the same copper cables. DSL can enhance the bandwidth of telephone line amazingly upto 8 Mbps by introducing various channels without disturbing the phone call.
DSL is the first Broadband technology used for Internet. In India, BSNL’s DSL Broadband service is very popular and cheaper across the India. DSL is also spreading in rural areas. DSL always requires a small DSL Modem for demodulation of received signals through telephone line. This modem usually comes in network architecture. It directly connects to PC through Ethernet port. It usually comes with DSL filter which separates Internet signals from telephone signals. Commonly, ADSL (Asymmetric Digital Subscriber Line) is preferred by users. The word asymmetric implies the asymmetry of uplink and downlink speeds. In ADSL, users get more downloading speed as compared to uploading speed. The next version of ADSL is ADSL2+ which offers speeds up to 24 Mbps. ADSL2+ is soon to arrive in India. DSL is dependent for distance from the telephone exchange as the strength of signal gets lost with increasing the distance. Thus, user far away from exchange gets lower speeds as compared to user nearer to the same. DSL also as application in IPTV which enables users to watch TV through telephone line set up with Broadband. The bandwidth of DSL cannot be increased upto very high extent due to noise issues.
2. Cable
Next to public switched telephone network (PSTN), television cable network is the second larger network spread in urban areas. This cable network is already set up for Broadband. Because, cable TV uses Broadband in which given bandwidth is shared by multiple simultaneous signals called as ‘channels’ or ‘bands’. Hence, this line can obviously be used for the purpose of Internet access. This cable is always a ‘Coaxial cable’. This cable is more secure and resistant to electromagnetic induction which causes signal loss in copper cable. The system or protocol used here is known as DOCSIS (Data over Cable Service Interface Specification). DOCSIS 1.0 offers speeds up to almost 38 Mbps which is much more than DSL. The recent version of DOCSIS is DOCSIS 3.0 which offers speeds up to 120 Mbps. Unlike DSL, cable Broadband is independent of the distance from exchange. Hence, every person anywhere in the cable network gets the same speeds. I think cable Broadband service would be more preferable than DSL. It also requires a modem which connects to the customer’s PC. This modem usually comes in network architecture. It directly connects to PC through Ethernet port. This service is also cheaper and affordable just like DSL. Presently in India, Sify Broadband and Hathway Cable offer the service of Cable Broadband in major cities.
3. Fibre-optic Cable
Even though copper cables and coaxial cables are widely being used for communication, there are certain limitations. These cables are becoming very expensive day by day. Thus in future, there should be certain replacement for these cables. Hence, for this purpose a new cable called as ‘optical fibre’ or ‘fibre-optic’ was invented. This cable is being used in many applications including communication sector. The cable is made up from fine quality glass like quarts. It is totally transparent cable. Unlike copper or coaxial cable, Fibre-optic cable doesn’t use electric pulses for transmission of signal. It uses light pulses. This light is always laser. The major advantage of this cable is that it provides very much high bandwidth enabling transmission of several simultaneous signals including voice, video, Internet, television signals etc. These cables are not subject to noise issues unlike DSL. Very fine-quality cables of fibre-optic are available in market right now. Also, these cables are very much cheap.
Fibre-optic provides speeds between 50 Mbps to 100 Mbps both in uplink and downlink. I think these cables are about to replace traditional copper and coaxial cables. Fibre-optic will really become revolution in case of wired communication.
4. Satellite
The DTH services have gained very much popularity because they have brought entertainment of television even in rural and remote areas. This direct satellite-to-home system can also be used for the access of Broadband Internet. It is estimated that there must be 75 million rural homes all over the world which have no Broadband Internet access. Hence in such areas, satellite Internet access will be perfect solution. It requires launching a separate Broadband satellite.
As per the information from BBC News Technology, two broadband satellites are being launched in Europe the next year. The first one is from UK firm ‘Avanti’. It is expected to offer speed of 2 Mbps for all the homes in UK with a very cheap cost. The second one is from French firm ‘Eutelsat’ which is expected to offer speed of 10 Mbps in entire UK. India is also soon to launch a new Broadband satellite for fixed Internet access all over the India. I will inform you after getting sufficient information about this.
The main problem with this system is ‘signal delay’ which increases the time for transmission and receipt of signal. This is because the signal has to travel almost 36000 km through air upto satellite. Also, the signal gets disturbed due to whether conditions like rain. But, it provides constant bandwidth throughout the access.
This was everything about fixed Broadband Internet access. The rest of article describes about some technologies about Mobile Broadband.
5. Mobile Broadband: 3G Family
The demand for Broadband Internet is increasing due to its cheapness and high-speed capability. The 3G family of GSM has two technologies which enable users to access Broadband Internet on the move. These technologies are HSPA (High Speed Packet Access) and HSPA+ (evolved High Speed Packet Access). HSPA is the upgrade to core 3G network (WCDMA) and can be treated as an extension to existing 3G networks. Often marketed as 3.5G, HSPA is the collection of two mobile telephony protocols namely, HSDPA and HSUPA. HSDPA handles the downlink while HSUPA handles the uplink. HSPA offers optimum downlink speeds upto 14.4 Mbps. The mobile operator may restrict this speed as per the payment of customer. This means less per month cost for 3.6 Mbps and more cost for 7.2 Mbps for a fixed data bundle (usually in GBs). The maximum uplink speeds are upto 5.76 Mbps. To access mobile Broadband through HSPA, you have to purchase a USB modem called as ‘dongle’ which is usually offered by mobile operator at affordable price. HSPA also comes in-built in cellphones, tablet PCs and even in laptops (netbooks). Many of these devices come with only HSDPA which provides only high downlink speed and uplink is handled by core 3G network at 384 kbps.
The upgrade to HSPA is HSPA+. HSPA+ uses a special communication technique known as MIMO (Multiple Input Multiple Output). MIMO is the use of multiple antennas both at receiver as well as transmitter. HSPA+ offers maximum theoretical downlink speeds upto 84 Mbps and maximum theoretical uplink speeds upto 22 Mbps. HSPA+ will enable several features like HD video streaming as well as conferencing. Many of the present HSPA (3.5G) networks in the world are being upgraded to HSPA+. Some of these networks operate at 21.1 Mbps while some at 28 Mbps. HSPA+ is also the extension to existing 3G services.
Well, we don’t have to wait for arrival of HSPA/HSPA+ services in India because these services are already being launched following the 3G spectrum auction. TATA DOCOMO and Reliance have launched their HSPA+ networks in India with speeds upto 21.1 Mbps and 28 Mbps respectively. BSNL is also upgrading its existing HSPA network to HSPA+ with peak speeds upto 21.1 Mbps.
6. Mobile Broadband: CDMA Family
The alternative mobile technology to GSM is CDMA (Code Division Multiple Access). Both GSM and CDMA have developed their 3rd generation of telephony especially targeted towards the enhanced data speeds. UMTS is the 3G of GSM. On the other hand, EVDO (Evolution Data Optimized/Only) is known 3G of CDMA. UMTS can handle both voice and data while EVDO service is optimized only for data. EVDO service is designed as an upgrade as well as an extension to existing CDMA 1x network. EVDO is backward compatible with 1x network. On the other hand, UMTS is not backward compatible with GSM/GPRS/EDGE. It is an compititor to 3G. EVDO offers maximum downlink speeds upto 2.4 Mbps and uplink speeds upto 153 kbps. This basic version of EVDO is known as EVDO Rev.0 in which only downlink is enhanced and uplink is handled by backward 1x network. The evolutionary upgrade to EVDO is known as EVDO Rev.A. Rev.A offers downlink speeds upto 3.1 Mbps and uplink speeds upto 1.8 Mbps. EVDO Rev.A network has been deployed widely all over the world including India. In India, Reliance communications (Netconnect+), Tata Teleservices (Tata Photon+) and MTS (MBlaze) have their EVDO Rev.A networks working upto speeds of 3.1 Mbps. The next upgrade is to EVDO is EVDO Rev.B which will be soon getting deployed. EVDO Rev.B has peak downlink speeds upto 4.9X Mbps and uplink speeds upto 1.8X Mbps where 'X' is the number of 1.25 MHz pieces of spectrum of used. EVDO also comes with a USB modem which is connected to PC for Broadband Internet access.
I think 3G will be better than EVDO considering many aspects such as speeds, network, cost etc.
WiMAX (Worldwide Interoperability for Microwave Access) is a new telecommunications protocol that enables user to access fixed and mobile Broadband Internet with speeds upto 40 Mbps. WiMAX will be an alternative to DSL, Cable, 3G and EVDO. WiMAX should not be confused with Wi-fi which is the wireless version of Ethernet and is a wireless networking protocol. Wi-fi is IEEE 802.11 specification while WiMAX is IEEE 802.16 specification. Pune city in India is soon to be a WiMAX city. More content will be uploaded after getting sufficient information.
Mobile broadband industry is getting cheaper day by day and many new technologies are coming for its enhancement. We will use it more and more in future.
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