Broadband access and Bidirectional Transformation Technology

Comparison of HFC, XDSL, wireless access ( LMDS ), Ethernet, optical fiber access mode of broadband access way which is more suitable?

Several broadband access way has its characteristic:

HFC ( hybrid fiber coax )

The advantages of HFC network not only to provide the original cable television business, but also to provide voice, data and interactive services. Because the cable network home has been very popular, local area and even over telephone penetration rate, so HFC is recognized to the information highway.

Compared with the traditional wired network, HFC network main innovation to establish service area ( SA ) concept. The entire network with optical node is divided into a service area. Modification of HFC with bidirectional transmission of digital media information, open the VODNVOD (VOD ), distance education, telemedicine, Internet/Intranet fast access and voice telephone new value-added service. Radio and television departments force to promote HFC technology.

Disadvantages of HFC cable TV network structure of a portion of the optical fiber data collection star network, cable section collects dendritic distribution network. This kind of network structure in broadband speed integrated services network is unreasonable, the main cause of CATV network integrated services network reliability for different, integrated information network for network reliability.

Cable distribution network transmission channel, active filter passive filter, cable joint, severe descending transmission system reliability.

Broadband speed integrated information network for data communication, bit error rate, and cable with shielding, so that no electromagnetic leakage cable connector. But cable TV network equipment as the demand.

Network management issues. Cable television network, are generally not make network automatic management. The network function is, on this account to reflect, two on network maintenance management regularly patrol monitoring. Broadband integrated information network and modern intelligent communication network, and has very reliable, has an automated network management, network performance, configuration, fault, billing and other comprehensive management, to improve operation efficiency of network quality of service.

XDSL

Advantage through existing copper twisted pair are respectively with a modem, which realizes the transmission rate is increased several times. XDSL technology not only makes the copper twisted pair medium speed digital communication field occupy on the ground, but also plays a very important role. Lev xDSL technology in broadband access service advantage is very clear, first, to take full advantage of the existing copper cable telecommunications network resources, and the user at any time, without afresh each time the connection is established, while not affecting the telephone so that, each household exclusive speed channel, no blocking problem. The xDSL access, confidentiality, security by.

Inferior xDSL line can provide the speed distance copper quality is very sensitive, especially the increase in distance, crosstalk crosstalk increased, so that the line quality deterioration. The other, a considerable number of copper wire mesh China due to aging and other quality problems can not withstand a transmission rate.

Ethernet

Advantages of Ethernet technology is mature, cost, simple structure, stability, good extensibility, easy network upgrade, at the same time to realize the real-time monitoring, intelligent property management, district / building / home security, home automation ( such as remote control home appliances, visual doorbell, remote meter reading, etc.), to provide intelligent, information office, home furnishing, different levels to meet the information needs of people. User, network speed, fee.

Disadvantages we should pay attention to, using high-speed Ethernet access facing end equipment, lack of IP address resource quantity, the operation and management level of a problem.

LMDS

LMDS (local distribution business ) Local Multipoint Distribution Services shrinkage, microwave broadband service, belonging to the wireless fixed access means, the characteristics in wideband characteristics. LMDS data transmission rate of 1.2Kbps ～155Mbps support, and support for the agreement, including ATM, TCP, frame relay and IP. LMDS 's own characteristics, decision is more suitable for the city or the more densely populated areas; because the work frequency, communication quality is affected by rain, snow and weather effects.

Optical fiber

( optical fiber direct access ) nearly arisen kind of broadband access way. The utility model has the advantages of wide bandwidth, in order to reach the GHz level.

If the use of radio and television network advantage, so only by Cable Modem. While Cable Modem has a frequency division technology, time division technology code technology, how to choose? Code technology user bandwidth slightly less than the other two, but because of no on line modification, and cost more, so we think that the code technology will be the mainstream Cable Modem technology.