Intenet Access Technologies in Srilanka

Internet access Technologies	Broadband	Narrow-band	Description
ADSL	Yes		Uses typical twisted pair cable that come home. Maximum downstream up to 8 Mbps. Divide the voice and data signals on the telephone line into three frequency bands.
Internet Leased Line	Yes		Internet leased lines are usually available at speeds of 64k, 128k, 256k, and 512k, T1 or E1). Any speed required. Permanently connected to the other
Optical Fiber	Yes		Technology which bring fiber step closer to the subscriber. In Sri Lanka vastly used in large organizations. Can go up to speed of up to 1 Gbps
HSPA	Yes		Supports data rates up to 14 Mbit/s in the downlink and 5.8 Mbit/s in the uplink. In Sri Lanka do not provide unlimited packagers.
Wi-Max	Yes		Can go for over a much greater range.  Point-to-multipoint last-mile internet access. Can go up to 11.3 Mbps. Good solution of people who cant get ADSL
LMDS	Yes		LMDS offers a microwave solution with a reduced cost per link. It transmits in a point to multi-point fashion over a wide coverage area.  LMDS channel is capable of 45 Mbps downstream.
CDMA	Yes		Can achieve maximum capacity of 2Mbps. Popular as wireless internet access technology in Sri Lanka.
Wi-Fi	Yes		Based on the IEEE 802.11x standard and transmitting in unlicensed spectrum at 2.4 GHz. support data rates up to 54 Mbps.
Dial-up		Yes	Uses the facilities of the public switched telephone network (PSTN). Use same frequency voice band of 0- 4 kHz. Few years ago very popular and only can have 56 kbps.
ISDN		Yes	Much faster speed of 256 kbits/s. But not considered as broadband. Not popular because had to use separate equipments.
WAP		Yes	Most use of WAP involves accessing the mobile web from a mobile phone. Can’t get much capacity through this wireless mobile technology.
GPRS		Yes	Can achieve maximum speeds of up to 9.6 kbps. This is mobile wireless technology.  Mainly used   for web browsing.

Access Network

 Access Network

We learn about basic network in basic telecommunication networks to understand their principals and operation. The main and the very important network is access network when someone on the basic learning.

An access network (Outside Plant) is the network that has series of wires, cables and equipment lying between a consumer and service operator. This is the only one network customer can see from this eyes. 

Block Diagram of Access Network

Exchange – Exchange is he center where the switching equipments and DSLAM placed. Switching equipment connects the customer to caller party by analyzing the dialed number. And DSLAM is used to provide the DSL service to customers. And MDF stands for main distribution frame. The MDF is a termination point within the local telephone exchange where exchange equipment and terminations of local loops are connected by jumper wires at the MDF. 

Street cabinet - Street cabinet is the device located in the street in between local exchange and the customer. Big size cables having much number of pairs are terminated at cabinets and they are distributed to different customer’s locations through smaller size cable having lesser number of cable pairs.

DP – DP stands for Distribution point. DP is used for termination of secondary telephone network to the subscriber drop or service line cable pairs.

Drop wire – Drop wire ends the access network. It is used to connect customer premises equipment with Distribution point.

Customer premises equipment (CPE) - customer premises equipment are Discharger, Rosette box, Splitter, and modem. 

Access Network

 

Today service operators supply additional services such as xDSL based broadband and IPTV (Internet Protocol Television) to customers using access network. The access network is again the main barrier to achieving high data rate to customers, because even though providers configure and update their core network there can be lot of issues in access network due to structure of the cabling and high attenuation. Without understanding or even knowing the characteristics of these enormous copper spider webs, it is very difficult, and expensive to connect new customers and assure the data rates required to receive next generation services.

Throughout this article I hope you may get some thing. This provides very basic explanation and future will cover more. Comments are well come. Thank you.