Interview Material

BlueTooth Interview Questions Answers

BlueTooth Interview Question - 1 : -

Give a generic description of Bluetooth?

BlueTooth Interview Answer - 1 : -

Bluetooth is a low-cost, short-range (RF) links between mobile PCs, mobile phones and other portable devices. Bluetooth can transmit through solid, non-metal objects.

BlueTooth Interview Question - 2 : -

Why can Bluetooth equipment integrate easily in TCP/IP network?

BlueTooth Interview Answer - 2 : -

Because Bluetooth uses wireless LAN standards IEEE for data transmission.

BlueTooth Interview Question - 3 : -

How many SCO links are there in a piconet?

BlueTooth Interview Answer - 3 : -

In a piconet, there can be up to three SCO links of 64,000 bits per second each.

BlueTooth Interview Question - 4 : -

What is Airport?

BlueTooth Interview Answer - 4 : -

Airport is a wireless communications system, like Bluetooth. It is based on the IEEE 802.11 recommendation. It also uses 2.4 GHz frequency band, but its range is about 45 meters and it boasts a transmission speed of 11 Mbit/second. It is developed by Lucent Technologies.

BlueTooth Interview Question - 5 : -

What are the other (competing or not) wireless technologies?

BlueTooth Interview Answer - 5 : -

Wi-Fi, IrDa, EDGE, UWB (Ultra Wide Band)

BlueTooth Interview Question - 6 : -

What is Piconet?

BlueTooth Interview Answer - 6 : -

A collection of devices connected through Bluetooth technology in an ad hoc fashion.

BlueTooth Interview Question - 7 : -

How secure a Bluetooth device is?

BlueTooth Interview Answer - 7 : -

Bluetooth uses the SAFER+ algorithm for authentication and key generation. The E0 stream cipher is used for encrypting packets. This makes eavesdropping on Bluetooth-enabled devices more difficult.

BlueTooth Interview Question - 8 : -

Why is Bluetooth 2.0 better?

BlueTooth Interview Answer - 8 : -

The main features of Bluetooth Core Specification Version 2.0 + EDR are:
• 3 times faster transmission speed (up to 10 times in certain cases)
• Lower power consumption through reduced duty cycle
• Simplification of multi-link scenarios due to more available bandwidth
• Backwards compatible to earlier versions
• Further improved BER (Bit Error Rate) performance

BlueTooth Interview Question - 9 : -

How many devices can communicate concurrently?

BlueTooth Interview Answer - 9 : -

A Bluetooth device playing the role of the “master” can communicate with up to 7 devices playing the role of the “slave”. This network of “group of up to 8 devices” (1 master + 7 slaves) is called a piconet. A piconet is an ad-hoc computer network of devices using Bluetooth technology protocols to allow one master device to interconnect with up to seven active slave devices (because a three-bit MAC address is used). Up to 255 further slave devices can be inactive, or parked, which the master device can bring into active status at any time.

BlueTooth Interview Question - 10 : -

Which Bluetooth version uses adaptive frequency hopping? Why?

BlueTooth Interview Answer - 10 : -

In Version 1.2 Adaptive frequency hopping method is used, which improves resistance to radio interference, and provides higher transmission speed.

BlueTooth Interview Question - 11 : -

What are Different Classes in Bluetooth?

BlueTooth Interview Answer - 11 : -

Bluetooth is a radio standard and communications protocol primarily designed for low power consumption, with a short range (power class dependent: 1 meter, 10 meters, 100 meters) based around low-cost transceiver microchip in each device.

Bluetooth lets these devices communicate with each other when they are in range. The devices use a radio communications system, so they do not have to be in line of sight of each other, and can even be in other rooms, so long as the received power is high enough.

BlueTooth Interview Question - 12 : -

What are some of the uses of Bluetooth?

BlueTooth Interview Answer - 12 : -

Depending on the Bluetooth profiles included on the device, Bluetooth technology has the capability to wirelessly synchronize and transfer data among devices. The Bluetooth audio capabilities can be used for headset and hands free applications. The exact functionality provided by a Bluetooth enabled device depends on the Bluetooth profiles included.

BlueTooth Interview Question - 13 : -

How does Bluetooth use frequency hopping for security?

BlueTooth Interview Answer - 13 : -

Bluetooth picks a random frequency out of 79 and then hops around the range about 1600 times per second.

BlueTooth Interview Question - 14 : -

What are Bluetooth profiles?

BlueTooth Interview Answer - 14 : -

A profile is a description of how to use a specification to implement a particular function. The International Standards Organization (ISO) first came up with the idea of profiles. In Bluetooth, there are several profiles available and they are arranged in a hierarchical fashion. For example, in order to use the headset profile, a device must also include the lower level profiles such as the serial port and general access profiles.