---

Many of us are drivers. We drive daily from home to office and vise-verse. We go on trips during our vacations or holidays; then we ought to drive long distances.
Anyway these days, especially in Sri Lanka, one of the main causes of road accidents is using mobile phones while driving. If you are a frequent driver and your vehicle has a modern stereo system, then you can use your mobile phone while driving!!! Well, it is pretty good that you don’t have obstacles that distract you while driving; but if you need to keep on driving while you are in a conversation with the party on the other side of the phone then the modern car stereos (who has Bluetooth facility) might be great advantage.

Nevertheless, you may think, having a Bluetooth Headset might be useful as well but if you have a stereo system that supports Bluetooth connection then you can do activities beyond a phone call. After connecting your mobile phone to the stereo via Bluetooth, you can keep the phone aside and operate it via the stereo interface. You can navigate through your phone contact lists, you can dial numbers and also you can play media files via the stereo’s console. I tend to use that facility because it’s not a burden for my driving especially when I need to answer an important phone call.

Anyway please make sure that you setup the phone and stereo before you start driving. If you can fully omit using mobile phones while driving (even with this technology) it is pretty handy.

The technology

However I thought it’s worth exploring the technology behind these modern car-stereos.  I know some of you might already use this feature, but it is good that you are aware of the technological background of it.

Modern car-stereo connects to your smartphone via Bluetooth (of course your mobile phone must have Bluetooth technology) and it can control your phone. It is dangerous to pay your attention to your stereo while driving; but once you have completed all the settings (in-order to keep the phone aside) you can make a move while answering the call you received.

Bluetooth:

Bluetooth is a technology used to connect digital devices which are in short range. It is a wireless protocol which is being used by devices which has Bluetooth ports. All modern mobile phones have this facility.  It was invented in 1994 by Ericsson. [1] Bluetooth operates in short range radio frequency band. Bluetooth comprises protocols in the likes of cable replacement protocol, telephony control protocol, and adopted protocol. Among the mandatory protocols we find, the one used to set-up and control radio link between two devices as well as the one used for audio/video remote control. [1]

Common applications of Bluetooth technology

•     You can connect your mobile phone to another phone or a computer using Bluetooth.
   
•     As you might already know, there are Bluetooth headsets that you can use with your mobile phone. By using the Bluetooth headset you are able to talk without your phone in hand, in a specific range.
   
•     Modern car stereo systems have the facility to connect to your mobile phone and it will make your life so easy while you are driving.

In this article I focus on the technology behind these car stereos that help us to use mobile phones.

Bluetooth has many profiles that help us to use it for various functions. For example if you consider streaming audio/video data from one device to other, then there is a specific Bluetooth profile for that, namely, Advanced Audio Distribution Profile (A2DP). To make use of these profiles, both devices must have Bluetooth version that supports the specific profile. Now, A2DP is essential to transfer audio data from your phone to the stereo; means that it’s a basic profile in the modern car stereos’ Bluetooth. There is another protocol, Hands-free Profile (HFP) which allows car hands-free kits to connect with the mobile phones in the car. Phone Book Access Profile (PBAP, PBA) allows you to synchronize your phone’s contact list with the stereo. Likewise there are many Bluetooth profiles (set of technological enhancements of Bluetooth) that you can use for different purposes. [2]

If you have one of these new car stereo setups in your car, then go to its menu option and select mobile phone to connect to your mobile phone. (This is of course if you have not used this feature earlier). Make sure you have switched on phone’s Bluetooth. If you have paired the two devices then the next time you bring these two devices closer enough to be connected, they will connect automatically [3]. These enhancements in the Bluetooth technology are very attractive so the modern day users are attached to them. You can read the technical specifications of a profile online, if you are interested.

(The writer is a software developer in an Australian company)