Difference Between Usb And Serial Connection

[prakashkadam 1]

What is the difference between serial and USB connection via R-Connect. Somebody pl.

[Vishal Gupta 4]

In case of speed, I think there is no diff.

both give good speed.

diff. is in their working only.

also some USB cables charge ur mobile phone during connetion.

[karpar 1]

I think the USB one is better...Don't ask me the reason though...I'm sure I knew it when I bought it!!!

[rajatng 0]

The two connections are really quite different at every level. Serial ports go back to the first PCs and provided transfer rates of 1 bit at a time(serially). A serial cable therefore has as little as two wires(one data and one ground if you only want to send data in one direction).

USB (Universial Serial Bus) is an improvement on the original RS-232C serial port in that it is MUCH faster. Also, multiple serial devices can share the same bus by being "daisy chained". That is one device plugs into the computer, the next device plugs into that device, etc. In practice, however, this is generally limited because the bus can only supply power for limited number of devices. Also, Windows has been programmed to automatically detect when devices are added or removed from the bus. That makes it especially useful for devices like digital cameras that may only be connected to the computer long enough to download pictures to the hard drive.

There are, however, converters that will allow you to connect different kinds of devices to the various kinds of ports. For example, Belden makes a parallel to USB converter (and software drivers) that allows parallel port printers to be connected to a USB port on a computer.

[spadival 0]

Another difference is that they stopped putting serial ports on laptops long ago !! So I ended up buying an expensive USB to serial cable off bazee.

[Saurav 22]

In case of speed, I think there is no diff.

for lg 2030 usb gives better speed but doen't work with bit pim

[Ashokjp 15]

Well USB cable cable with Bitpim has worked for some people..

I guess member "Chandramauli" got that done..

[Ganesh 0]

USB cable can support 230Kbps connecion,where as serial will connect at max 115k.so if your os supports 230kbps internet(linux supports this and windows does not afik)its better for usb.i have original usb cable and it works only at 115k.there was an article in pc-quest magazine that how to make 230kbps connection with reliance phone for internet.

[deepu 0]

This is the article that came in PCQuest

Internet connects using Reliance cellphones

To use your Reliance cellphone as a modem, you first need to activate data calls in it. To do so dial *412 and wait for a confirmatory SMS. Then get a data cable (easily available from any mobile shop for about Rs 250, for all models of Reliance CDMA phones) and connect your cellphone to your PC/laptop. We tested this on PCQLinux 2004 using Samsung’s N191 CDMA phone. Kudzu (the hardware-detection tool for Linux) will automatically detect the phone as a USB/COM modem, depending on which data cable interface you’ve connected it with, once your OS reboots. Now, you have to configure the wvdial.conf file to dial to the Net. For accessing the Internet, all CDMA providers use a standard number (#777). Now create a dialer in /etc/wvdial.conf which will dial to this number. Don’t use any graphical utility to create it as it may not work

properly. The contents are:

[Modem0]

Modem = /dev/input/ttyXYZ

Baud = 230400

SetVolume = 0

Dial Command = ATDT

Init1 = ATZ

FlowControl = Hardware (CRTSCTS)

[Dialer cdma]

Username = your_phone_number

Password = your_phone_number

Phone = #777

Stupid Mode = 1

Inherits = Modem0

In the second line, replace ttyXYZ to ttyS0 (For Com1) or ttyS1 (For Com2). If you are using the USB interface, then replace it with ttyACMx. Here x is the number of devices minus one, which you have connected to your USB port. If you have three USB devices connected, then x= 2. Remember that if the number of devices change, then the value of x also changes. You can also find its value by running the usbview command.

Now enter the number of the cellphone you are using, along with the STD code of the home circle, without the first 0, in both the username and password fields. Enter #777 in the Phone field. Don’t forget the Stupid Mode = 1 line or your modem will not work. Now, run the following command from any terminal.

#wvdial cdma

Here, cdma is the name of your dialer (the line [Dialer cdma] in the wvdial.conf file). You can replace cdma with another name.

If you have another modem in the machine, then it will need a similar block of its own in the wvdial.conf file. Obviously, depending on the type of modem and the phone line used, the values in the block will change.