Communication Protocols
RF communication for LEGO/Handy Board with Tmote
http://venom.cs.utsa.edu/dmz/techrep/2008/CS-TR-2008-006.pdf
LEGO robots with Handy Board controllers have limited connection capability. This paper describes
enhancing the Handy Board controller with Tmote for radio-frequency (RF) communication capability
which allows the building of LEGO robots that have wireless communication capability. The MIT Handy
Board has a simple interface with LEGO components and rich functionalities of connecting other
digital/analog I/O devices. However, the wireless communication capability of Handy board is rater
limited which is needed for other LEGO robots to communicate with each other or with the host PC.
The Handy Board is based on the Motorola MC68HC11 microprocessor and has a rich set of
functionalities, and a 32K battery-based static RAM with a built in NiCad rechargeable battery pack. It
also has a LCD screen with several input/output devices and the possibility for an expansion board in
order to increase the number of I/Os. Although the Handy Board does have IR as one of its I/O devices,
this is not good with LEGO communication as it requires direct pointing and restricted to small distances.
The Tmote Sky sensor can provide wireless communication as it possesses an on-board antenna which
can provide up to 125m (410.10 feet) of coverage. It uses USB protocol to connect with a host machine.
In order for the Tmote to connect with the Handy Board, the RX, TX, and found pins must be connected.
Once this is complete the HB and TM need to be programmed individually in order to exchange data.
TMCP: Two-layer multicast communication protocol for Bluetooth radio networks
http://wireless.cs.tku.edu.tw/~cychang/TMCP.pdf
Bluetooth devices are low cost, low power, and short-range wireless communication technologies. A
piconet is a group of Bluetooth communication devices where there is one master device and up to seven
slave devices in communication. In the communication network, a master stays in an inquiry state and
obtains the information about a slave’ Bluetooth address, time stamp, etc. The master then moves into a
page state when switching to the channel derived from the slave’s information. In the page state, the
master sends a slave a frequency hop synchronization packet containing a 3-bit active member address.
The masters Bluetooth address and clock information helps the slave to derive hop sequence where as the
AM_ADDR is used for the slave’s identification then the communication link is constructed. A bridge is
a Bluetooth device that participates in more than one piconet. It relays messages between piconets and
can be in one mode, slave/slave or master/slave. In the slave/slave mode, the each member plays the
slave mode in alternating piconets whereas in the master/slave role, in one piconet a member is a master
and in the other it is a slave. Figure 1.
Bluetooth scatternets are where multicast services provide data transmissions from source device to
several predefined member devices which may belong to different piconets. A multicast protocol is
required to construct an efficient multicast tree from source to all members. There are three features of a
multicast tree:
1. The tree contains as few as possible the non-member nodes in order to reduce power, band width
consumption, and propagation(broadcast).
2. The height is minimized for reducing propagation delay.
3. Contains as many as possible shared links for reducing bandwidth consumption.
This paper proposes a Two-layered Multicast Communication Protocol that applies the role switching
techniques to construct an efficient multicast tree. The basic concepts of multicast tree construction is that
it must take into account the characteristics of role and hopping sequence in a Bluetooth network, the root
is the source where each piconet has exactly seven member slaves in order to minimize the height and all
internal nodes join two piconets, one in the upstream and one in the downstream. Each will play a
slave/master role (FIG 6)
flood-based mechanism is also incorporated. This is where given a scatternet the flooding mechanism
broadcasts a request from source node for constructing a multicast tree. On the request, each bridge
device switches to another piconet and forwards the message to the other devices in that piconet.
However the role of the multicast members needs to be changed, requiring the application of TMCP, a
two phase protocol.
In phase one, a multicast tree is constructed by flooding the route search packets over the given scatternet
and assigns a proper role to each tree node. In order to do this, given a source s, which enters the page
scan state and waits for new downstream links with members that receive the route search package in the
downstream piconets. member and non-member devices execute different operations in order to complete
this phase. The non-members forwards search packets to its neighbor nodes where members deal with the
up-link and down-link connection. To do this, information sent by the source s is extracted and the nonmember replaces this information with his personal time stamp and address, then sends it to its neighbors
while the member devices stay in page scan mode. In phase 2 role switching operations are used to
recognize the topology of the constructed multicast tree to collect member nodes into some piconet. In
this phase the member has to switch roles. In other words, this means that two masters in two different
piconets swap connections with the slave. In order to do this, the slave broadcasts a query packet to its
children who reply with a info packet of their children and asks them to connect to the root.
The relationship between the constructed multicast tree and the original scatternet
Member switch
Communication Protocols Testability Improvement by Narrow Input/Output (NIO) Sequences
http://www.iaeng.org/IJCS/issues_v34/issue_1/IJCS_34_1_5.pdf
Optimizing Layered Communication Protocols
http://www.cs.cornell.edu/Projects/spinglass/public_pdfs/Optimizing%20Layered.pdf
WIRELESS COMMUNICATION PROTOCOL BASED ON EDF FOR
WIRELESS BODY SENSOR NETWORKS
http://usuario.cicese.mx/~luisvi/Papers/JART_WBSN_2008.pdf
A k-Anonymous Communication Protocol for Overlay Networks
http://discovery.csc.ncsu.edu/pubs/ASIACCS07b.pdf
QMP : A Fast Communication Protocol for COW’s
http://www.facweb.iitkgp.ernet.in/~badri/papers/qmp.pdf
CORBA® BASICS
http://www.omg.org/gettingstarted/corbafaq.htm#TotallyNew