Managing Telecommunications

Telecom & IS Organization

IS departments have been responsible for designing, building, and maintaining the information Just as governments are responsible for building and

maintaining streets, roads, and freeways

Telecom provides infrastructure for moving information and messages Internet opened up a new view of telecom of providing a

cyberspace

Telecom History

Circuit-switching network PSTN (POTS) Suitable for analog voice signals Overhead of establishing a temporary circuit

(seconds) tolerable

Packet-switching network Aimed at transmitting data Messages are sent in packets Assume the intelligent user devices

The Evolving Telecommunications Scene The Internet can handle all kinds of intelligent

user devices PDAs, VoIP phones, gaming consoles, wireless

devices, PCs... The Internet allows these device to handle

different kinds of services Voice, e-mails, graphics, gaming...

The global telecom infrastructure is changing from a focus on voice to a focus on data

Transformation of Telecom Industry (1) The telecom structure of old was originally

provided by (often Government owned) monopolies (e.g. AT&T)

Gradually, the telecom industry has been deregulated

Telecom industry is even more competitive than computer industry Bandwidth on fiber is now doubling capacity every four

months

Transformation of Telecom Industry (2) The last mile problem for RBOCs in 1990s

A Fire-hose-to-straw gap tbps (1012) in backbones VS. 56k or 1.2m in the

last mile (Figure 6-1) RBOCs then became ILECs, and there came

new competitors CLECs (competitive LECS) ILECs bundled local phone access with Internet

access CLECs came up with new connection options

Cable modems, optical fiber, wireless, satellite…

Telecom Technologies and Their SpeedsBits Per Second Technologies

1011-1012 Optical fiber

1010 Optical wireless local loop(20G), WMAN (100G)

109 Microwave LANs (1.5G-2.0G), Gigabit Ethernet (1G), WMAN (24g)

108 ATM (155-622M), Faster Ethernet (100M)

107 Frame relay (10M), Ethernet (10M), WLANs(10M), cable modem (10M), Wi-Fi (11-54M)

106 Stationary 3G (2M), DSL(1.5-7M), WiMax (1.5-10M)

105 Mobile 3G (384k), ISDN (128k)

104 Modems (56k), 2.5G(57k)

103 2G (9.6-14.4k)

Case Example: ICG Communications This CLEC provides voice and data services in 25

metropolitan areas in the United States It was formed in 1984 to provide local telephone

service in Denver. It expanded to provide long distance, buying up

companies with fiber routes It later focused on being an Internet backbone

provider, serving ISPs When the dot-com bubble burst, ICG filed for

bankruptcy, but moved out of bankruptcy in late 2002

Acquired by Level 3 Communication in 2006

The Internet is the Network of Choice (1) Internet and telecom surprised us by its fast

rise and fall in the past one decade

History of the Internet In 1960s, APARNET developed by DOD for

transferring scientific files Mainly used for email

Until 1993, still an all-text world-wide network for scientists and academics Email, FTP, Telnet, Gopher…

The Internet is the Network of Choice (2)

In 1994, Tim Berners Lee invented World Wide Web URL HTML Browser

The Internet has done for telecom what the IBM PC did for computing: brought it "to the masses"

Open architecture of Internet Interconnectivity

The Internet is the Network of Choice (3) 3 important attributes of the Internet

Ubiquity Global reach

Reliability Alternate routing, scale-free network

Scalability Easy extension of its reach, increasing performance of

websites

The Internet is the Network of Choice (4) Intranet

Internet technology used inside an enterprise

Extranet Internet technology

used to connect trading partners, customers, suppliers etc.

EIntranet

Extranet

Public Website

Digital Convergence

Intertwining of various forms of media – voice, data and video

All forms of media can be digitized, put into packets and sent over an IP network Media managed and manipulated digitally and

integrated in highly imaginative ways

IP Telephony (1)

The use of Internet to transmit voice to replace their telephone system A phone with an IP address, voice delivered in digital

packets

Previously conceived application of IP telephony To another IP phone on the LAN Through the company's WAN to a distant IP phone on

another of the company's LANs Through an IP voice gateway to the PSTN to a

standard telephone

IP Telephony (2)

IP Telephony (3)

IP Telephony (4)

Video Telephony

Similar story to IP Telephony Not video conferencing via a PBX, but rather

video over IP With the appropriate IP infrastructure, video

telephony can be, say, launched from an instant-messaging conversation IP phones with cameras also facilitate it, phone to phone

IPTV

IPTV is television content that, instead of being delivered through traditional broadcast and cable formats, is received by the viewer through IP networks. Standards used: MPEG2, MPEG4/H.264, MPEG2-TS IP,

UDP, RTP, TCP, etc.

Voice

Data

Video IPConverged services over copper or fiber

ContentProvider

ServiceProvider

DeliveryNetwork

HomeNetwork

OSI Reference Model

Closed VS. open network Closed network: using proprietary networking

technology Open network: based on national or international

standards

What is a reference model? A division of functionality together with data flow

between the pieces No detailed standards specified for each layer

An Analogy: Mailing a Letter

Information encapsulated Envelop vs. packet

Control information on the envelop Address, services

Each layer wraps the message with its own layer of control information Headers

Reversed unwrap at the receiving end

Seven Layers

HTTP

NetBIOS

SSL

TCP

IP, X.25

Ethernet, Token ring, FDDI, ISDN, ATM, Frame relay

10BaseT, twisted pair, fiber-optic cable

Application Layer

Presentation Layer

Session Layer

Transport Layer

Network Layer

Data Link Layer

Physical Layer1

2

3

4

5

6

7

Important protocols

The Physical Layer

Responsibility: Transmission of raw bits over a communication

channel. Issues:

Mechanical and electrical interfaces Time per bit Distances

The Data Link Layer

Responsibility: Data Link Control sub-layer: provide an error-

free communication link MAC sub-layer: provides DLC with “virtual

wires” on multiaccess networks. Issues:

framing (dividing data into chunks) header & trailer bits

addressing

10110110101 01100010011 10110000001

The Network Layer

Responsibilities: Path selection between end-systems (routing). Subnet flow control. Fragmentation & reassembly Translation between different network types.

Issues: Packet headers Virtual circuits

The Transport Layer

Responsibilities: Provides virtual end-to-end links between peer

processes. End-to-end flow control

Issues: Headers Error detection Reliable communication

The Session Layer Establishes, manages, and terminates sessions

between applications. The Presentation Layer

Data encryption, data compression, data conversion

The Application Layer Anything not provided by any of the other layers

Connecting Network

Repeater: physical layer

Bridge: data link layer

Router: network layer

Gateway: network layer and above.

Repeater

Copies bits from one network to another Does not look at any bits Allows the extension of a network beyond

physical length limitations

REPEATER

Bridge

Copies frames from one network to another Can operate selectively - does not copy all frames

(must look at data-link headers). Extends the network beyond physical length

limitations.

BRIDGE

Router Copies packets from one network to another. Makes decisions about what route a packet

should take (looks at network headers).

ROUTERROUTER

Gateway

Operates as a router Data conversions above the network layer. Conversions:

encapsulation - use an intermediate network

translation - connect different application protocols

encrpyption - could be done by a gateway

The Optical Era Will Provide Bandwidth Abundance Decline in cost of key factors

During the industrial era: horsepower Since the 1960s: semiconductors Now: bandwidth

40 million miles of fiber optic cable have been laid around the world, in the USA at a rate of 4,000 miles per day Half of the cable is dark, that is, it is not used. And the

other half is used to just one-millionth of its potential Over the next decade, bandwidth will expand ten times as

fast as computer power and completely transform the economy

The Wireless Century Begins

The goal of wireless is to do everything we can do on wired networks, but without the wire

Wireless communications have been with us for some time Mobile (cell) phones, pagers, VSATs, infrared

networks, wireless LANs etc. Radio waves are none-deterministic

The 20th century was the Wire-line Century, the 21st will be the Wireless Century

Licensed VS. Unlicensed Frequencies Some frequencies of the radio spectrum are

licensed by governments for specific purposes; others are not

Devices that tap unlicensed frequencies are cheaper No big licensing fees Greater competition, more innovation and faster

changes Possibility of collision between signals

"Telecoms Crash"

Auctions of the 3g radio spectrum in Germany and Britain at the beginning of 2000. Although one similar auction in the USA had failed disastrously the year

before. 3G also requires an infrastructure development measured in billions of

dollars The nature of the auctions, was to offer a limited number of

licenses This put the telephone operators in a difficult position, as diabetics being

forced to bid for insulin. The stock market lost confidence (dot-com crash), influencing

the credit rating of the operators Within a year 100,000 jobs were lost in telecoms in Europe

(30,000 in UK) Subsequent government auctions of the 3g spectrum were met

with low bids

Wireless Networks (1)

Wireless Personal Area Networks (WPANs) Provide high-speed connections between devices that are

up to 30 feet apart Wireless Local Area Networks (WLANs)

Provide access to corporate computers in office buildings, retail stores, or hospitals or access to Internet "hot spots" where people congregate

Wireless Metropolitan Area Networks (WMANs) Provide connections in cities and campuses at distances

up to 30 miles Wireless Wide Area Networks (WWANs)

Provide broadband wireless connections over thousands of miles

Wireless Networks (2)

Wireless Long Distance (1)

The only two wireless technologies are infrared light and radio airwaves Cell phone and cellular

network

1G cellular Using analog technology and

circuit switching Main targeted at voice

service In the main, GSM has

become the mobile telephony standard

Wireless Long Distance (2)

2G cellular Predominant today, uses digital technology, but

still circuit switched 2G can carry SMS service It aims at digital telephony, but with certain ability

to carry data 2.5G (e.g. GPRS)---2.75G (e.g. CDMA)

Adds data capacity to a 2G network The problem with adoption has been pricing

Wireless Long Distance (3)

3G Services include wide-area wireless voice telephony

and broadband wireless data, all in a mobile environment. 802.11 networks are short range

384k-2M Costs to deploy not seen as tenable in many

circumstances It faces the same pricing issues at 2.5G – perhaps

worse Killer apps still not clear Battery and input

Wireless Long Distance (4)

4G A comprehensive IP solution where voice, data and

streamed multimedia can be given to users on an "Anytime, Anywhere" basis

Features higher data rates than previous generations: 100M-1G (any two

points in the world) premium quality and high security Fully IP-based Supporting a greater number of wireless devices that are directly

addressable and routable (IPv6) Spectrally efficient and high network capacity

Pre-4G technologies WiMax, LTE, UMB...

Coming: An Internet of Things Wireless communications like promised by

4G will enable machine-to-machine Internet Sensor network RFID tag Devices are all connected to the Internet, with a

mix of wired and wireless technologies

A new business environment

The Role of the IS Department Three roles of IS department

Create the telecom architecture Connectivity Interoperability

Operate the network Stay current with the technology

Conclusion

The telecom world is complex, and getting more complex every day

The business world is becoming increasingly dependent on telecom In the past, electronic data exchange The Internet unleashed email Web sites were then used to get noticed globally Now it is used for transaction and business

The first generation of the Internet economy has been wired.

The second is unwired