The controller devices initiate communications and make requests or commands of responder devices. The responder device performs the requested action and transmits a response back to the controller device. A single responder device can take on both controller and responder roles, providing the option of peer to peer communications.
Amplitude-shift keying (ASK) is a form of amplitude modulation that represents digital data as variations in the amplitude of a carrier wave. In an ASK system, binary symbol 1 is represented by transmitting carrier wave of fixed amplitude and fixed frequency for the bit duration T seconds.Any digital modulation scheme uses a finite number of distinct signals to represent digital data. ASK uses a finite number of amplitudes, each assigned a unique pattern of binary digits. Usually, each amplitude encodes an equal number of bits. Each pattern of bits forms the symbol that is represented by the particular amplitude. The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the amplitude of the received signal and maps it back to the symbol it represents, thus recovering the original data. Frequency and phase of the carrier are kept constant.Faraday's law describes how a time varying magnetic field creates ("induces") an electric fieldAmpère's law with Maxwell's correction states that magnetic fields can be generated in two ways: byelectrical current (this was the original "Ampère's law") and by changing electric fields (this was "Maxwell's correction").
This power limits the area of the network to a piconet, between 0.5 metres (1.6 ft) and 30 metres (98 ft)
The Controller is considered permanently "Awake" and to have a power supply provided by a permanent source. The Responder is made to work on battery and alternate between "Listening" and "Sleeping" states.The Responder, in the "Listen" state, tries to detect a carrier at 131 kHz and to read its commands. An emitting Controller in ASK sends a low power carrier for a zero bit whereas in BPSK the carrier is always present at the maximum emitting power. Thus, the Responder can detect the communicating Controller and stay listening. If there are many Responders and if the Controller uses only the one-to-one Request PDU, the Responder will stay listening for all commands sent and received on the network, and therefore may stay permanently awake. The use of responder groups, multicast or broadcast, help to better manage battery life for the Responders. An optimization for the cost and sleeping period of the Request PDUs must be done on the application layer.
and help to distinguish even signals with orthogonal interference.Controller and responder must be Syncronize otherwise network not able to distinguish between different -2 signal
Mesh networks generally refer to wireless networks. Mesh networks are networks where each wireless node talks to one or more wireless nodes. Each node will repeat packets of information, thus increasing the effective range of the network. Communication between nodes will travel in hops between nodes to (ideally) achieve the shortest number of hops, between 2 points.P2P generally refers to 'Peer to Peer' filesharing networks. Each user shares and downloads files from and to each other. P2P sometimes refers to a 'Point to Point' wireless network. That is each node communicates exclusively with another node. This is generally done with directional antennas over larger distances.
By 'harsh environment' we mean situations in which one or both ends of the communication is near steel or waterseparated by "nulls", angles where the radiation falls to zero.
Advantage over RFID
• It’s a wireless data communication protocol based
on IEEE 1902.1.
• RuBee is proposed for high security applications
and use in harsh environment.
• It uses long wave magnetic signal to send and
receive short data packets .
• Similar to the IEEE 802 protocols .
• But uses low frequency carrier(<450 kHz).
• RuBee is networked by using on-demand, peer-topeer, active radiating transceivers.
Rubee Physical layer
• For modulation ASK and BPSK with phase
shifts of 0 degrees or 180 is used.
• The Controller must support both modulation
but the Responder may only support one.
• Bi-phase Mark Coding (BMC), Manchester
Encoding technique is used for encoding.
• It can operate at other frequencies (< 450 kHz)
but 131 kHz is optimal.
• The IEEE 1902.1 recommends devices to have an
average power of less than 10 milli-Watts (mW).
• Magnetic signals drop off 1/R3 (R distance from
antenna) so will not travel nearly as far as the RF
• RuBee tags have very low power consumption.
• Operating over medium range (0.5 to 30 meters)
and at low data transfer speeds (300-9600 bits
• The communications between controller devices
and responder devices uses near field.
• Two kind of Protocol data unit (PDU): Request
PDU and Respond PDU .
• Controller send Request PDU ,its address and
command to responder.
• Responder process the command and send
response PDU to controller.
• Response PDUs are less than half the length of
the request PDU.
• This facilitates the use of physically smaller and
less expensive batteries in responder devices
state transitions in responder
• The Controller is always
"Awake“ connected with a
permanent power supply
• The Responder is used
battery and switching
between "Listening" and
• In the "Listen" state
responder tries to detect a
carrier and read the
command to process.
• Responder is always awake
If the controller uses oneto-one request PDU.
• BMC encoding on BPSK modulation allows
synchronizing the listening of the carrier on a
specific Responder or Controller signal.
• The listener device have two listening
channels with 90º phase difference .
• No anti-collision mechanism like CSMA/CA .
• So Controllers and Responders must be
Network and Application Layer
• Peer-to-Peer network topology is used .
• Network size is 8 (node).
• RuBee tag use an 8 nibble address (32 bit) like
ip address which define tag as a unique.
• AES is used for encryption.
• Frame checking sequence is done on
application layer due to system simplicity .
Advantage over RFID
• RFID work in the VHF, UHF or SHF
bands with the electric field.
RuBee is 99.99% magnetic waves
so not effected by people or
animals, mud or water.
• Steel can enhance a magnetic
signal. Long Wavelength magnetic
transmissions (below 1 MHz) is
not blocked or reflected by steel
so nulls do not occur.
• Magnetic signals drop off 1/R3 (R
distance from antenna) so noise
is also falls off 1/R3.
• Due to short range its also safe in
• In harsh environment like steel
block the Radio waves and create
problems like RF nulls .
• Radio signals and RFID power
drops off 1/R in far field so noise
is also falls off 1/R.
Rubee tag Design
• A RuBee Tag has a 4 bit CPU
• It could optionally have
sensors ,displays and
• RuBee is bidirectional, ondemand, and peer-to -peer.
• It can operate at other
frequencies but 131 kHz is
• The RuBee protocol uses an
IP Address and unique MAC
to communication with
other tags and RuBee
• Long battery life: The IEEE 1902.1 recommends devices
to have an average power of less than 10 milli-Watts
• Human Safety: A RuBee base station produces only
nano watts of radio energy.
• Cost effective : low frequency is used so less amount of
money required for deployment .
• Less noise : magnetic signal falls off 1/R3(R distance
• Better transmission distance: RuBee antennas read all
tags in a specified volumetric area, regardless of which
way the tags are facing, or what is around the tag .
• There is no data protection mechanism like
• Data range (15 m) and data rate (9.6 kb/s) is
• Access mode is not available like CSMA/CA.
• Rubee is used magnetic single so it can be
used in harsh environment .
• RuBee has a high degree of security
• Also the power consumption of RuBee is low
therefore it can be used for a long time.
• Design and Application of RuBee-based Telemedicine
Data Acquisition System by Xiaohua Yu*, Xiangling
Xia, Xuhui Chen* in 2011.
• A Comparative Study of Short Range Wireless Sensor
• Network on High Density Networks by Mahdi
Zareei1*, Azar Zarei2, Rahmat Budiarto3, Mohd. Adib
Omar4 in 2011.