Interview Questions.

Q1. How Does Bluetooth Fit In With Wifi?

The 802.11b (WiFi) wellknown is typically used for wireless networking. Bluetooth is not a competitor with 802.11b, however instead a supplement to it. While 802.11b is usually a substitute for stressed out neighborhood place networking, Bluetooth is greater usually used as a alternative for cables among man or woman devices. Bluetooth is designed to link gadgets inside a very short variety (up to 33 feet ). Bluetooth is a part of the 802.15 fashionable.

Q2. What Are Different Classes In Bluetooth?

Bluetooth is a radio standard and communications protocol generally designed for low energy intake, with a short range (electricity elegance established: 1 meter, 10 meters, one hundred meters) primarily based round low-value trceiver microchip in each device.

Bluetooth we could those gadgets speak with every other when they're in range. The gadgets use a radio communications system, in order that they do not ought to be in line of sight of each other, and may also be in different rooms, as long as the acquired energy is excessive enough.

Q3. Will Other Rf (radio Frequency) Devices Interfere With Bluetooth Devices?

No. Bluetooth radios perform at the unlicensed 2.Four GHz (Industrial, Scientific and Medical) frequency band that is shared among different gadgets (microwave ovens, cordless telephones, garage door openers, and so forth. ). Bluetooth radios switch frequencies at this sort of fast tempo (1,six hundred instances consistent with 2d) and the statistics packets are so small that interference from different RF assets is exceedingly not going. Bluetooth is a robust conversation machine.

Q4. Define Dos Attack?

Denial Of Service assault. It tries for making computer assets unavailable to its intended customers. Its concerted efforts of a person are to prevent a site or carrier from functioning efficiently, briefly or indefinitely. The target site classes are banks, credit card payment gateways and root call servers.

Q5. Name Few Applications Of Bluetooth?

Wireless manipulate of and communique between a mobile cellphone and a palms unfastened headset or vehicle package. This is the maximum popular use.

Wireless networking between PCs in a constrained area and in which little bandwidth is required.

Wireless communications with PC input gadgets inclusive of mouses and keyboards and output devices inclusive of printers.

Trfer of documents among devices through OBEX.

Trfer of contact info, calendar appointments, and reminders between devices via OBEX.

Replacement of traditional stressed serial communications in test device, GPS receivers and medical system.

For far off controls where infrared changed into historically used.

Sending small classified ads from Bluetooth enabled marketing hoardings to other, discoverable, Bluetooth devices.

Wireless manage of a games console, Nintendo's Wii and Sony's PlayStation 3 will each use Bluetooth generation for his or her wi-fi controllers.

Sending instructions and software to the imminent LEGO Mindstorms NXT in place of infra purple.

Q6. Will Bluetooth And Wireless Lan (wlan) Interfere With Each Other?

No, each Bluetooth and WLAN can co-exist. Since Bluetooth gadgets use Frequency Hopping and maximum WLANs use Direct Sequence Spreading strategies they each seem as heritage noise to the other and need to no longer reason any perceivable overall performance problems.

Q7. What Is The History Of Bluetooth?

Bluetooth changed into initiated with the aid of Ericsson, IBM, Intel, Nokia and Toshiba in early 199@These organizations later shaped a special interest organization referred to as the Bluetooth SIG. The Bluetooth 1.Zero specs have been launched on July 26, 1999, but the era has handiest currently end up cheaper enough for tremendous use.

Q8. How Many Devices Can Communicate Concurrently?

A Bluetooth device playing the role of the “master” can talk with up to 7 devices playing the position of the “slave”. This community of “institution of up to eight devices” (1 grasp + 7 slaves) is known as a piconet. A piconet is an ad-hoc laptop network of devices the usage of Bluetooth era protocols to permit one grasp device to interconnect with as much as seven energetic slave devices (due to the fact a 3-bit MAC deal with is used). Up to 255 similarly slave devices can be inactive, or parked, which the grasp device can convey into active popularity at any time.

Q9. Define Bluetooth Dongle?

Bluetooth dongle is a technology that enables a PC for factor to multi-factor pleasant connectivity with other similar Bluetooth gadgets, like PDA, mobile telephone. The gadgets allow the communique among devices inside various 30 feet apprx.

Certain recent computers and laptops are integrated with Bluetooth dongle to speak. Bluetooth enables a unmarried adapter to permit more than one gadgets for speaking with one device to another.

Q10. What Is Pairing?

Pairs of gadgets might also establish a relied on dating with the aid of mastering (via consumer enter) a shared mystery known as a “passkey”. A device that wants to communicate only with a trusted device can cryptographically authenticate the identification of the opposite device. Trusted devices may encrypt the statistics that they alternate over the air so that nobody can listen in.

The encryption can but be grew to become off and passkeys are saved at the tool's report system and no longer the Bluetooth chip itself. Since the Bluetooth cope with is everlasting a pairing can be preserved even supposing the Bluetooth name is changed. Pairs may be deleted at any time by means of either tool. Devices will generally require pairing or will spark off the owner earlier than it lets in a far flung device to use any or maximum of its services. Some gadgets consisting of Sony Ericsson telephones will typically take delivery of OBEX enterprise cards and notes with none pairing or activates. Certain printers and access factors will permit any tool to apply its offerings by way of default much like unsecured Wi-Fi networks.

Q11. Can You Please Explain The Difference Between Bluetooth And Infra Red?

Connectivity: One-to-one connections are made through infrared gadgets, while Bluetooth devices can shape while all of the gadgets have recognized themselves to every other. 

Versatility: Bluetooth devices ought to work together; in which as infrared devices want to be especially designed for particular devices.

Range: Class three Bluetooth devices works at approximately 30 feet; while infrared is rated at three feet.

Orientation: Infrared devices are direct line-of-sight; wherein as Bluetooth devices may want to communicate even in times of separation through barriers. Security: Bluetooth is less at ease than infrared due to the omni directional nature; in which as infrared signals could best be intercepted by means of a tool.

Q12. What Is Bluetooth Sig?

Bluetooth Special Interest Group (SIG) :  Bluetooth wireless generation is revolutionizing personal connectivity by offering freedom from stressed out connections. It is a specification for a small-form aspect, low-fee radio solution imparting hyperlinks between cell computers, cell phones, different portable hand-held gadgets and cars, as well as connectivity to the Internet.

The Bluetooth SIG, made out of leaders within the telecommunications, computing, car and client electronics industries, is riding improvement of the era and bringing it to marketplace.

The Bluetooth SIG consists of Promoter member businesses Agere, Ericsson, IBM, Intel, Microsoft, Motorola, Nokia and Toshiba, and hundreds of Associate and Adopter member agencies. The Bluetooth SIG, Inc. Headquarters are placed in Overland Park, Kas, U.S.A.

Q13. What Are Some Of The Uses Of Bluetooth?

Depending on the Bluetooth profiles blanketed at the device, Bluetooth technology has the functionality to wirelessly synchronize and trfer facts amongst gadgets. The Bluetooth audio talents may be used for headset and palms free programs. The actual capability furnished with the aid of a Bluetooth enabled device relies upon at the Bluetooth profiles blanketed.

Q14. What Is It - A Technology, A Standard, An Initiative, Or A Product?

Bluetooth wireless era is a de facto widespread, as well as a specification for small-shape aspect, low-value, quick variety radio hyperlinks between cell PCs, cell phones and other portable devices. The Bluetooth Special Interest Group is an enterprise group which include leaders inside the telecommunications, computing, and networking industries which are using development of the generation and bringing it to market

Q15. Define Cabir Worm?

Cabir bug is one of the malicious software, generally referred as malware. It makes use of Bluetooth generation for sending itself to another similarly prone tool. As it is self-replicative, is it classified as a worm.

Cabir worms are presently impacts mobile phone which makes use of the Symbian Series 60 User Interface Platform and feature Bluetooth wireless technology.

Q16. What Is The Range Of Bluetooth Trmitter/receivers?

Bluetooth is designed for extremely low energy use, and the trmission variety will handiest be 10m, about 30ft. High-powered Bluetooth devices will permit degrees as much as 100m (300ft). Considering the design philosophy in the back of Bluetooth, even the 10m range is ok for the functions Bluetooth is meant for. Later versions of the Bluetooth spec might also permit longer tiers.

Q17. Define Bluetooth Profiles?

Order to describe the way of imposing person fashions accomplishments, the profiles are evolved. A quantity of consumer situations are described by means of the person models where Bluetooth performs the radio trmission. Profile stack describes the options in every protocol that are mandatory for each profile, and defines range of parameters for every protocol. The profiles are worried for reducing the hazard of interoperability issues amongst numerous products of different producers.

Q18. What Types Of Companies Are Likely To Adopt Or Promote Bluetooth Technology?

Companies probably to undertake this generation include, but are not confined to, software developers, community carriers, silicon vendors, peripheral and digital camera manufacturers, cell PC and handheld device producers, client electronics manufacturers and extra.

Q19. What Companies Are Involved In The Bluetooth Initiative?

Global era leaders Ericsson, Nokia, IBM, Intel and Toshiba based the Bluetooth SIG in 199@These companies at the moment are supported by means of over 1,000 different organizations with a huge range of knowledge, along with Widcomm, Inc.

Q20. Is Bluetooth Practical For Use With Mobile Devices?

Yes. One difficulty for mobile computing customers is strength consumption. Bluetooth radios are very low strength, drawing as little as 0.3mA in standby mode and 30mA all through sustained statistics trmissions. Bluetooth radios trade among strength-saving modes wherein device interest is lowered to maximize the mobile energy supply.

Q21. What Kind Of Encryption Will Be Used For Bluetooth Security?

The Bluetooth specification 1.0 describes the link encryption algorithm as a movement cipher using 4 LFSR (linear feedback shift registers). The sum of the width of the LFSRs is 128, and the spec says “the effective key length is selectable between eight and 128 bits”.

This arrangement permits Bluetooth for use in countries with policies restricting encryption energy, and “facilitate a destiny improve course for the safety with out the want for a high-priced redecorate of the algorithms and encryption hardware” in line with the Bluetooth specification. Key era and authentication seems to be the use of the 8-spherical SAFER+ encryption set of rules.

The facts available indicates that Bluetooth safety will be adequate for maximum purposes; however customers with better security requirements will need to appoint stronger algorithms to make certain the safety in their data.

Q22. What Are Bluetooth Profiles?

A profile is an outline of the way to use a specification to enforce a particular function. The International Standards Organization (ISO) first got here up with the concept of profiles. In Bluetooth, there are several profiles to be had and they're organized in a hierarchical fashion. For example, which will use the headset profile, a tool should also consist of the lower degree profiles together with the serial port and trendy get admission to profiles.

Q23. Are Different Brands Of Bluetooth Products Compatible?

Yes. They have to. The Bluetooth Logo Certification Program requires Bluetooth products to interoperate with products synthetic by means of different companies; those products that do not interoperate will not be allowed to use the Bluetooth emblem.

Q24. How Secure A Bluetooth Device Is?

Bluetooth makes use of the SAFER+ set of rules for authentication and key era. The E0 flow cipher is used for encrypting packets. This makes eavesdropping on Bluetooth-enabled gadgets greater hard.

Q25. What Is The Data Throughput Speed Of A Bluetooth Connection?

Bluetooth trfers statistics at a rate of 721 Kbps, that is from three to 8 instances the common speed of parallel and serial ports, respectively. This bandwidth is capable of trmitting voice, information, video and nonetheless photographs

Q26. What Is Lmp (link Management Protocol)?

Multiple statistics links are combined for the formation of a unmarried site visitors engineering hyperlink, for the motive of scale capability. The in-band messaging isn't limited through the control of TE links, but may be used by the usage of out-of-band strategies.

The Link Management Protocol runs between a couple of nodes and is utilized for coping with TE links. LMP is specially used for retaining manipulate channel connectivity, verifying the physical connectivity of the facts links, correlating the hyperlink belongings facts, suppressing downstream alarms and localizing the link disasters for protection/healing functions.

Q27. What Are The Problems With Older Versions (1.Zero And 1.0 B)?

Versions 1.0 and 1.Zero B had numerous problems and the various manufacturers had exceptional difficulties in making their merchandise interoperable. 1.Zero and 1.0B additionally had mandatory Bluetooth Hardware Device Address (BD_ADDR) trmission within the handshaking manner, rendering anonymity not possible at a protocol degree, which changed into a chief setback for services deliberate for use in Bluetooth environments, including Consumerism.

Q28. Define Ip Spoofing?

Sending messages via intruder to a laptop system with an IP deal with that suggests the message is sent from a trusted host, for gaining unauthorized get entry to to pc systems. The hacker/intruder first make use of a ramification of techniques for locating an IP cope with of a depended on host. Later he modifies the packet headers, to be able to deliver an illusion that the packets are sent from the host.

Q29. Describe Ldap And Also Define Its Uses?

Lightweight Directory Access Protocol is one of the directory service protocols. It runs over TCP/IP. LDAP directory services implements a customer/server model. Directory data is to be had on one or greater LDAP servers. The server responds with a pointer to every other LDAP server.

Uses: LDAP allows the users to get right of entry to the records inside the listing to alternate. Online telephone directories and electronic mail directories are some of the uses of LDAP. LDAP listing has utilities to regulate, delete, and search the entries.

Q30. Can You Please Explain The Difference Between Power Classes In Bluetooth?

Device Power Class, Max Output Power (mW), Max Output Power (dBm), Expected Range

Class 1, 100mW, 20dBm, 100m.

Class 2, 2.5mW, 4dBm, 10m.

Class 3, 1mW, 0dBm, 10cm.

Q31. Is Bluetooth An Ieee Standard, Like Ieee 802.11 And Ethernet?

Being an IEEE preferred will be a big plus to large adoption of Bluetooth, and IEEE 802.15 working organization for non-public area networks (PAN) introduced that they'll be adopting Bluetooth as the IEEE 802.15 popular.

Q32. Why Is Bluetooth 2.Zero Better?

The most important capabilities of Bluetooth Core Specification Version 2.Zero + EDR are:

3 instances faster trmission pace (up to 10 instances in positive cases)

Lower strength intake thru decreased responsibility cycle

Simplification of multi-link eventualities because of greater to be had bandwidth

Backwards like minded to earlier variations

Further improved BER (Bit Error Rate) performance