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Q # 4 Name shabeer Email shabeerswati@YAHOO.COM Max Tech Computer Institute

This Question was sent on 8/24/2006 3:12:52 PM

Question : Dear Shah Hussain Sab. Plz tell me some thing abt Broadband communication, and HFC network. Thanks

Answer: Dear Brother Shabeer Sb. Thanks for visiting our web site forum. I am sending you some valuable definitions for your Questions. I am sending this form the book "COMPUTER NETWORKS and internets with internet Applications". Hope it will help you. 1)- Broadband Technologies. Engineers have used frequency division multiplexing to build a variety of network technologies that permit independent communications to proceed simultaneously over a single underlying medium. For Example, the transmitters and receivers used with some wireless networks can be tuned to a specific channel, making it possible to have two independent sets of computers in a single room communication at the same time. One set communicates on Channel 1 at the same time that the other set communicates on Channel 2. The primary motivation for using frequency division multiplexing arises from the desire for high throughput. to achieve higher throughput, The underlying hardware uses a larger part of the electromagnetic spectrum (i.e.. a larger bandwidth). Thus, the term broadband technology is used to characterize such technologies. The alternative, any technology that uses a small part of the electromagnetic spectrum and sends only one signal at a time over the medium. is known as BASEBAND technology. 2)- HFC (Hybird Fiber Coax). This is one of the most promising technologies that provide tow-way communication across a cable system is known as HFC. As the name implies, the system uses a combination of optical fibers and coaxial cables, with fiber used for the central facilities and coax used for the connections to individual subscribers, In essence. HFC is hierarchical. It uses fiber optics for the portion of the network that requires the highest bandwidth. and uses coax for parts that can tolerate lower capacities. To use HFC, cable companies will need to replace mush of the existing cable wiring and amplifiers. the industry uses the term trunk to refer to the high-capacity connections between the cable office and each neighborhood area, and the term feeder circuit to refer to the connection to an individual subscribers. it requires the cable company to replace trunk circuits with optical fiber. in addition, new equipment must be added that interfaces the fiber to coax. To permit upstream communication. the company must vantage of HFC, each subscriber needs a bidirectional cable modem. As with other cable technologies, HFC uses a combination of frequency division multiplexing and time division multiplexing. Bandwidth between 50 and 450 MHz is used for analog Television (width 6 MHz devoted to each TV channel), and bandwidth from 450 MHz to 750 MHz is reserved for downstream digital communication. Finally, the bandwidth from 5 through 50 MHz is used for upstream communication. Time division multiplexing operates within a group of one or more subscribers that are assigned to share the bandwidth. Usually. a group is chosen on the basis geographic proximity (e.g., in a neighborhood). The group shares on carrier frequency . with only one subscriber in the group able to receive a packet at any time. The higher bandwidth of fiber makes it possible to multiplex several independent groups across the trunk lines. Like ADSL, cable modems are designed to provide higher rates downstream than upstream. The data rate for upstream. The data rate for upstream delivery can be as high as 1.5 to 2.0 Mbps. However, because the data from multiple subscribers must be multiplexed into a 6 MHz bandwidth, the effective rate declines when many users transmit data simultaneously. Simply, To use Hybrid Fiber Coax, cable companies must change much of the central infrastructure. Trunk lines must be replaced with optical fiber, and all amplifiers must be modified to operate in both directions. However, the system can use existing coax feeder circuits to reach individual subscribers.

Responder name Shah Hussain Email shahhussain305@yahoo.com Response was sent on Tuesday / 29 / 8 / 2006

Q # 3 Name Shabeer Email shabeerswati@yahoo.com Max Tech Computer Institute

This Question was sent on 8/7/2006 5:30:57 AM

Question : Any courses offer abt communication, e.g Computer Networks, Broadband communication, Wireless LANS??

Answer: hello dear Shabeer Sb. Thanks for visiting our website. Currently we are offering the Computer Networks course only.

Responder name Shah Email shahhussain305@yahoo.com Response was sent on Tuesday / 8 / 8 / 2006

Q # 2 Name RAHAT Ali Email rahatbat@yahoo.com Max Tech Computer Institute

This Question was sent on 6/2/2006 5:03:53 AM

Question : Dear Shah Hussain Khan, Pls send me the code how to reterive data from access, 2ndly send me the code for online forum, Thanks

Answer: <%@ LANGUAGE="VBSCRIPT" %>  <html> <head> <title>Data Retriving form MS Access Database</title> </head> <body> To retrive data from access database there are many method but i will use the simple ADO with custom ASP in DSNLess Method. step 1- Make a database name db1.mdb make columns (name,email) save the table name as (info) then save theh database in the wwwroot directory of your system. Step 2- Now the enter some names and email address in the database db1.mdb table info. Step 3- The Code is retriving data from the database is as below <br> <% dim con,ors set con = server.CreateObject("ADoDB.Connection") con.ConnectionString ="DRIVER={Microsoft Access Driver (*.mdb)}; DBQ= " & Server.MapPath("db1.mdb") con.open set ors = Server.CreateObject("ADoDB.RecordSet") ors.open"info",con,2,3 if ors.EoF then %> <hr><b>Result</b><br> <font color=red>Sorry no record found.</font>. <% Else %> <hr><b>Result</b><hr><br> <table border=1 width="70%"> <% do while not ors.EoF %> <tr> <td>Name = <%= ors.Fields("name").value %> </td></tr> <tr> <td>Email = <%= ors.Fields("email").value %> </td> </tr> <% ors.MoveNext loop %> </table> <% End if ors.close set ors = Nothing con.close set con = Nothing %> </body> </html>

Responder name shah Email shahhussain305@yahoo.com Response was sent on Thursday / 15 / 6 / 2006

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