The Differences Between Bluetooth, ZigBee and WiFi

What is the Best?BlueTooth

ZigBeeWiFi

ZigBee

By: Mostafa Ali

Bluetooth[1]

• Bluetooth briefly is a short range and mobility product• It’s a short-range wireless technology that lets you connect

computers, mobile phones, and handheld devices to each other it can used in high-quality voice transmission in wireless headsets

• Creating personal area networks(PANs) with high levels of security with a medium data rate of 1 to 3Mbps

Bluetooth[2]

• Its indoor range is typically 2–10 meters• Communicating on a frequency between 2.402 and 2.480• 100+KB memory• Created by telecom vender Ericsson in 1994• Transmitting data via low-power radio waves• Using a radio technology called frequency-hopping

spread spectrum

Bluetooth[3]

• Using Point-to-multipoint(Star topology)• The big draw of Bluetooth are that it is wireless,

inexpensive and automatic• Connection happen when device come within range of

one another the electronic conversation happens automatically

• Bluetooth systems create a Personal Area Network(PAN) after conversation occurred and this called Piconet

Bluetooth[4]

• A master Bluetooth device can communicate with up to seven devices in a Piconet

• Devices can switch roles, by agreement, the slave can become the master at any time

Bluetooth[5]

• It use in a lot of devices like mouse, keyboards, printers and to communicate between mobile phones and a hands-free headsets

• Use of Bluetooth is to transfer files, contact details, reminders, appointment dates between devices

• Removal of traditional wires in test equipment, bar code scanners and medical equipment

ZigBee[1]

• ZigBee is a standard that defines a set of communication protocols for low-data-rate short-range wireless networking

• ZigBee-based wireless devices operate in 868 MHz, 915 MHz, and 2.4 GHz frequency bands

• The 868 MHz band is used in Europe, the 915 MHz frequency band is used mainly in North America, whereas the 2.4 GHz band is used worldwide.

• The maximum data rate is 250 K bits per second• ZigBee is targeted mainly for battery-powered applications

where low data rate, low cost, and long battery life are main requirements

ZigBee[2]

• In many ZigBee applications, the total time the wireless device is engaged in any type of activity is very limited; the device spends most of its time in a power-saving mode, also known as sleep mode .

• As a result, ZigBee enabled devices are capable of being operational for several years before their batteries need to be replaced.

• Design for wireless controls and sensors networking • ZigBee provides the most power and the most cost-

efficient solution compared to Bluetooth and IEEE 802.11b

ZigBee[3]Network layers and it’s relationship with IEEE802.15.4 Standards

• One of the common ways to establish a communication network (wired or wireless) is to use the concept of networking layers.

• Each layer is responsible for certain functions in the network.

• The layers normally pass data and commands only to the layers directly above and below them.

• These network layers shown in (Figure 1).

ZigBee[4]

ZigBee[5]

• As shown in Figure, the bottom two networking layers are defined by the IEEE 802.15.4 standard. This standard is developed by the IEEE 802 standards committee and was initially released in 2003.

• IEEE 802.15.4 defines the specifications for PHY and MAC layers of wireless networking, but it does not specify any requirements for higher networking layers.

• The ZigBee standard defines only the networking, application, and security layers of the protocol and adopts IEEE 802.15.4 PHY and MAC layers as part of the ZigBee networking protocol

ZigBee[6]Device types and device roles

• There are two types of devices in an IEEE 802.15.4 wireless network: full-function devices (FFDs) and reduced-function devices (RFDs).

• In an IEEE 802.15.4 network, an FFD device can take three different roles: coordinator, PAN coordinator, and device. A coordinator is an FFD device that is capable of relaying messages. If the coordinator is also the principal controller of a personal area network (PAN), it is called a PAN coordinator . If a device is not acting as a coordinator, it is simply called a device .

ZigBee[7]Networking Topologies

• In the star topology(point to multi points), every device in the network can communicate only with the PAN coordinator.

• In a peer-to-peer topology(mesh topology) (see Figure 2), each device can communicate directly with any other device if the devices are placed close enough together to establish a successful communication link. Any FFD in a peer-to-peer network can play the role of the PAN coordinator

• One way to decide which device will be the PAN coordinator is to pick the first FFD device that starts communicating as the PAN coordinator

ZigBee[8]

• In a peer-to-peer network, all the devices that participate in relaying the messages are FFDs because RFDs are not capable of relaying the messages. However, an RFD can be part of the network and communicate only with one particular device (a coordinator or a router) in the network.

WiFi[1]

• Short for wireless fidelity. • It is a wireless technology that uses radio frequency to

transmit data through the air.• Wi-Fi is based on the 802.11 standard:• 802.11a• 802.11b• 802.11g• 802.11n

WiFi[2]

• 802.11 is primarily concerned with the lower layers of the OSI model.

• Physical Layer Physical Layer Convergence Procedure (PLCP).

• to map the MAC frames onto the medium

Physical Medium Dependent (PMD).• to transmit those frames.

• Data Link Layer Logical Link Control (LLC). Medium Access Control (MAC).

WiFi[4]802.11b Standard

• Well-supported, stable, and cost effective, but runs in the 2.4 GHz range that makes it prone to interference from other devices (microwave ovens, cordless phones, etc) and also has security disadvantages.

• Limits the number of access points in range of each other to three.

• Has 11 channels, with 3 non-overlapping, and supports rates from 1 to 11 Mbps, but realistically about 4-5 Mbps max.

• Uses direct-sequence spread-spectrum technology.

WiFi[5]802.11a Standard

• Completely different from 11b and 11g.• Flexible because multiple channels can be combined for

faster throughput and more access points can be co-located.• Shorter range than 11b and 11g.• Runs in the 5 GHz range, so less interference from other

devices.• Has 12 channels, 8 non-overlapping, and supports rates

from 6 to 54 Mbps, but realistically about 27 Mbps max• Uses frequency division multiplexing

WiFi[6]802.11g Standard

• Extension of 802.11b, with the same disadvantages (security and interference).

• Has a shorter range than 802.11b.• Is backwards compatible with 802.11b so it allows or a

smooth transition from 11b to 11g.• Flexible because multiple channels can be combined for

faster throughput, but limited to one access point.• Runs at 54 Mbps, but realistically about 20-25 Mbps and

about 14 Mbps when b associated• Uses frequency division multiplexing

WiFi[7] 802.11n Standard

• The newest IEEE standard in the Wi-Fi category is 802.11n. It was designed to improve on 802.11g in the amount of bandwidth.

• 802.11n adds technology called multiple-input multiple-output (MIMO), a signal processing and smart antenna technique for transmitting multiple data streams through multiple antennas. The result? Up to five times the performance and up to twice the range compared to the earlier 802.11g standard.

• 802.11n connections support data rates of over 300 Mbps.• Runs in the 2.4 and 5 GHz range.

WiFi[8] Which one to choose?

• (A) 802.11a Frequency- 5 GHz  Typical Data Rate - 23 Mbit/s  Max Data rate – 54 Mbit/s  Range –30 m(100ft) outdoors

Cost: highest cost.

• (B) 802.11bFrequency - 2.4 GHz  Typical Data Rate - 4.5 Mbit/s  Max Data rate – 11 Mbit/s  Range - 95 m(300 ft) outdoors

Cost: lowest cost.

• (G) 802.11gFrequency - 2.4 GHz  Typical Data Rate – 19 Mbit/s  Max Data rate - 54 Mbit/s  Range – 95 m(300 ft) outdoors

Cost: costs more than 11b.

• (N) 802.11nFrequency - 5GHz and/or 2.4GHz  Typical Data Rate - 74 Mbit/s  Max Data rate - 300 Mbit/s (2 streams)Range–190 m(600 ft) outdoors

Cost: costs more than 11g.

WiFi[9]

Basic Security Strategies

• Block your Service Set Identifier (SSID) from being broadcast.• SSID that allows to identify the service network; it is a 32

bytes character string of a variable size.• SSID is used in order to guarantee the authentication and the

identification between an AP and a client.• Wireless beacon so PCs can easily find the access point.• Change the default network name in the access point.• Change the default access point password.• Center the access point in the middle of the building, house or

any other place.

WiFi[10]Media Access Control (MAC) Filtering

• Every network device has a unique MAC address• Allocated by the manufacturer.• MAC Filtering only allows certain addresses access. • Mostly for home use.• Tedious to implement on a large scale.

WiFi[11]Wired Equivalency Protocol (WEP)

• Basic encryption technology.• Uses an RC4 stream cipher.• Pseudo-random bytes.• Two versions: 64-bit and 128-bit versions.• Built into Wi-Fi certified equipment.• Implemented at the MAC level.• Protects radio signal between device and access point.• Does not protect data beyond the access point.• Uses static encryption keys.• Easy to crack. • Still better than nothing.

WiFi[12]Wi-Fi Protected Access (WPA)

• Designed to replace WEP.• Firmware update. • 128-bit Temporal Key Integrity Protocol (TKIP) encryption. • Uses a master key that is regularly changed.• User authentication.• Data Integrity.• Protects radio signal between device and access point.• Built into Wi-Fi certified equipment.• Implemented at the MAC level.• Available in two versions:

• WPA2 Personal.• WPA2 Enterprise.

WiFi[13]& Wi-Fi Protected Access 2 (WPA2)Extended EAP

• Designed to replace WEP.• 128-bit Advanced Encryption Standard (AES).• Based on the IEEE 802.11i standard.• Provides government level security.• Also available in two versions:

• WPA2 Personal.• WPA2 Enterprise.

• EAP - Extensible Authentication Protocol.• Addition to the Wi-Fi Protected Access. • Used in internal network.• Extra security for enterprise and government Wi-Fi LANs.• Several versions available

WiFi[14]Virtual Private Network (VPN)

• Creates a secure virtual “tunnel” from remote device to VPN server.

• Creates an encryption scheme.• Requires authentication.• Works across the internet.• Many types and levels of VPN technology.• May include hardware and software components.• Some very expensive.• Windows provides a basic implementation in its server

software.

WiFi[15]Firewall

• Can make the network or computer invisible to the internet.• Block unauthorized users.• Monitor and control flow of data to/from a network or computer.• Many types and levels of firewall technology. Hardware and software combinations Software only versions.

• ZoneAlarm• enables a personal firewall that can be configured with various levels of security

• Many devices provide basic firewall capability. Gateways and access points. Network address translation. Windows XP operating system.

WiFi[16]Kerberos

• Network authentication based on key distribution.• Nodes provide their own authentication.• Checks for data stream integrity.• Checks for modification.• Uses Data Encryption Standard (DES).• Any combination of these security techniques can be

used.• The more security the more of a hassle.

• Important when supporting users.

Distribution of the costs of a WLAN solution (souceWLANA). This figure illustrates clearly that a great part of the costs relates to the used physical material (1: downtime, 2: expenses, 3: management, 4: development of applications, 5: outsourcing, 6: material)

WiFi[17]

References

• WI-Fi, Bluetooth, Zigbee and Wimax by Houda Labiod, Hossam Afifi, Costantino De Santis.

• ZigBee Wireless Networks and Transceivers by Shahin Farahani

• 802.11® Wireless Networks: The Definitive Guide by Matthew Gast.

• IEEE Standard for Information technology—Telecommunications and information exchange between systems—Local and metropolitan area networks—Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.

• Wi-Fi Security by Stewart S. Miller.