420 likes | 725 Vues
POWER LINE COMMUNICATION: A new horizon in broadband communication. COMPILED BY: SARADENDU KARMAKAR ROLL NO.: 07/EE/15 SEC: A DEPT. OF ELECTRICAL ENGINEERING, NIT DURGAPUR. TOPICS OF DISCUSSION. BROADBAND: A REVIEW BROADBAND OVER POWER LINE TYPES OF PLC PLC: A TECHNICAL OVERVIEW
E N D
POWER LINE COMMUNICATION:A new horizon in broadband communication COMPILED BY: SARADENDU KARMAKAR ROLL NO.: 07/EE/15 SEC: A DEPT. OF ELECTRICAL ENGINEERING,NIT DURGAPUR
TOPICS OF DISCUSSION • BROADBAND: A REVIEW • BROADBAND OVER POWER LINE • TYPES OF PLC • PLC: A TECHNICAL OVERVIEW • APPLICATION AREAS OF PLC • PLC: SOME SHORTCOMINGS • PLC: PRESENT SCENARIO • CONCLUSION • REFERENCES
Broadband refers to a telecommunication signal of greater bandwidth, than another standard or usual signal. • A huge volume of the communication networks around the world, use internet as the standard means of data transfer. • The internet traffic over the last few years show an enormous growth over the last few years. 1. BROADBAND: A review
Internet broadband lines are mainly provided by, telecommunication companies, over existing DSL lines, or cable TV networks. • Data from research Teleography shows that Internet traffic has grown 62 percent in 2010 alone. A plot of the annual growth rate of the total internet traffic volume.
The DSL lines may not be able to handle the enormous increase in the internet traffic volume. • Such huge growth of data volumes also requires huge improvements in the existing network infrastructure, which is very difficult.
The existing problem with infrastructure, can be overcome, by use of the power lines, for data transfer. This is known as “Power line Communication” or “Broadband over Power Line”. • PLC works by transmitting high frequency data signals through the same power cable network used for carrying electricity power to household users. 2. BROADBAND OVER POWER LINE
It is cheap and convenient, as it uses the existing network, which is both widespread and capable of wide bandwidth. • This technology began as simple scheme for telemetering and control of electrical equipments in a network. • PLC is now being considered as a potential “third wire” in the broadband marketplace.
Access PLC: This uses electrical distribution lines, overhead or underground, to provide broadband Internet access to homes and businesses. • This is currently in the developmental stage • In-building PLC: This uses the electrical wiring within a building to network computers. 3. TYPES OF PLC
Control PLC : This operates below 500 kHz, and is used by electric-utility companies to control their equipment using the power-lines as transmission lines. • These systems are not a problem, although it is interesting to note that utilities are successfully lobbied against an amateur VLF allocation, claiming that amateur transmissions could disrupt their communications.
PLC works by transmitting high frequency data signals through the same power cable network used for carrying electrical power to household users. • This requires devices that combine the voice and data signals with the low-voltage supply current in the local transformer stations. • The signal makes its way to neighborhoods and customers who could access it , through utility poles. 4. PLC: A technical Overview
Digital Powerline use a network, known as a High Frequency Conditioned Power Network(HFCPN), to transmit data and electrical signals. • The CU sends electricity to the outlets in the home and data signals to a communication module or "service unit". The service unit provides multiple channels for data, voice, etc. • Base stationservers at local electricity substations connect to the Internet via fiber or broadband coaxial cable. The end result is similar to a neighborhood local area network.
Data from the internet domain is never directly fed into the electrical power lines. It is rerouted through an isolator/coupler, which serves the purpose of isolating the two signal bandwidths as well as the voltage levels. The isolator is generally connected to an electronic package (an injector or an isolator). This is a combination Isolator and Electronics package. The Electronics package can be an Injector or Repeater.
The Digital Powerline base station is a standard rack mountable system designed specifically for current street electricity cabinets. • Typically, one street cabinet contains twelve base station units, each capable of communicating with over 1 of 40 possible radio channels. • Several options, with different costs, can provide broadband Internet service to each base station. 4.1. THE SERVER
The simplest solution is connecting leased lines to each substation. • A wireless system has also been suggested to connect base stations to the Internet. This option reduces local loop fees, but increases hardware costs. • Another alternative involves running high bandwidth lines, along side electric lines, to substations. These lines could be fiber, ATM, or broadband coaxial cable. This option avoids local loop fees, but is beset by equipment fees.
The CU uses band pass filters to segregate the electricity and data signals, which facilitate the link between a customer’s premise and an electricity substation. • The CU contains three coupling ports. • The device receives aggregate input from its Network Port (NP). This aggregate input passes through a high pass filter. • Filtering allows data signals to pass to a Communications Distribution Port (CDP). • A low pass filter sends electric signals to the Electricity Distribution Port (EDP). 4.2. THE HFCPN CONDITIONING UNIT
The service unit is a wall or table mountable multi-purpose data communications box. The unit facilitates data connections via connectors to cable modems and telephone connections via standard line termination jacks. The service unit provides its own line power for ringing and contains a battery backup in case of power outage. 4.3. Service Unit
PLC offers end-users a broad spectrum of applications and services including broadband Internet access, voice over IP, multimedia services, telecommunication, home automation and energy management(near energy services). 5. APPLICATION AREAS OF POWERLINE COMMUNICATIONS
It is the use of powerline to transmission of voice data services. • PLT has been seen as a very attractive new area due to the following reasons: • The power grid is ubiquitous; it constitutes an existing network infrastructure to billions of private consumers and businesses. • The power grid offers last-mile conductivity. • The power grid supports information based services with strong growth potential. 5.1. POWERLINE TELECOMMUNICATION
Home plug networking is an attempt to integrate home appliances such as TV’s Refrigerators, Computers,etc., via the home electrical network. • As every electrical appliance already has a port connecting it to the electrical supply, it can be used to connect them with each other. 5.2. HOME PLUG NETWORKING: THE INCEPTION OF SMART GRID
Smart grid technology, uses the same principle to connect this devices, centrally to an enormous intelligent system, which can greatly increase the efficiency of modern power grids.
The most obvious use of PLC is internet access. • The high bandwidth is very convenient for high speed data access, and for protocols like, TCP/IP, VoIP, etc. • Simply by connecting to one’s power outlet, one can access speeds of about 14 mbps, which is provides a cheap and convenient means of internet access. 5.3. INTERNET
Near energy services are defined as energy services with in the confines of current business which ads new forms, features and scales. • Examples are remote billing, remote metering, demand side e management distribution automation and remote control of supply. • Advantages of such system for utilities lie in their potential for cost cutting and improving customer loyalty 5.4. POWER MANAGEMENT: Near energy services
Some other applications include: • Automated meter reading – customer usage can be monitored and billing completed without a visit to the home • Fault location and outage detection – BPL devices can alert the utility to possible failures in the power grid • Security and surveillance – the BPL network can provide video monitoring of substations and other utility buildings.
Electro-Magnetic Radiation Issues: • Power line solution, like telephone and DSL connections become unwanted source of electromagnetic radiation. • Emissions can potentially cause interference with radio, television, community antenna television, telephone and DSL services. • However, second generation PLC technologies are using techniques like OFDM (Orthogonal frequency-division multiplexing), which substantially reduces this problem. PLC: SOME SHORTCOMINGS
Addressing Issues: • With the increase in the number of connected subscribers to the PLC, the addressing of each device becomes more and more complex. • The solution schemes to such problems may include upgradation of the data protocols to IPV6, or Next Generation Internet Addresses (IPNG), so that an unlimited number of address space can be generated.
Noise Interference: • Power line communication is vulnerable to noise interference, due to the non-linear response of electronic devices to the power system. • Problems of harmonics and non-linear noise, is a big problem for PLC. • This can be solved by either using repeaters or dynamic change of frequencies.
SECURITY: • The transmission of data over a network that anybody has access to could also pose a data security problem. Tapping the signal could allow somebody to eavesdrop on communications. • Options like data encryption eliminates the problem.
Trends in both the electric and telecommunications industry have lead to a climate where PLC should be a big player. • These trends include • demand for affordable and high speed Internet access. • deregulation of electrical utilities. • demand for integrated and intelligent networks • BPL has rapidly grown to be a major player, as it utilizes existing networks and provides high speed data service at par with DSL and cable connections. PLC: PRESENT SCENARIO
Also, digital Power line offers a deregulated utility several options and advantages.
BPL is an exciting emerging technology, for broadband communication, and data services. • It utilizes existing power networks, which makes it cost effective and efficient. • By providing services like, PLT, TCP/IP, VoIP, Home plug networks etc., it serves as a multipurpose utility. CONCLUSION
However, it has some problems regarding widespread implementation. • Requires complex equipments for coupling the data signals with the power lines. • Requirement of repeaters for PLC, makes it costly for long distance communication. • Regulatory and legal issues are not yet suitable for this kind of communication. • However, with time, PLC may become a major phenomenon in the broadband market.