Bluetooth networking with Apple devices

klapdorothypondΚινητά – Ασύρματες Τεχνολογίες

23 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

55 εμφανίσεις

Bluetooth networking with Apple devices

Melanie Hendricks, Richard Watson, Dale Musser, Ph.D., Matthew Dickinson



Device “F” is connected to the
Scatternet

through “E”

I’m looking for “E”

If “E” moves, “F” loses connectivity to the
Scatternet
. “F”
can start broadcasting that it lost its’ parent “E”.

I have a route to “E”

Device “A” is nearby and responds that it
knows Device “E”. “F” then rejoins the
Scatternet
, and its’ new parent is “A”.

Staying Connected

Abstract


Mobile computing devices have become powerful platforms
for rich applications, and the Internet. By the end of July
2010, Apple will have sold 100 million
iOS

devices. With all
of these devices comes the need to network and share
information. Wireless technologies such as Wi
-
Fi and 3G
offer high bandwidth and great range, when they are
available. In situations where these radio services are
unavailable, Bluetooth radio is the best solution. Bluetooth is
a wireless technology that has been used for small devices
such as wireless headsets for cell phones, and wireless
printing on laptops. Bluetooth has largely been ignored in
the field of network communications, most likely due to the
shorter broadcast range when compared to Wi
-
Fi. However,
in today’s social gathering spaces, the range can be more
than adequate. By creating networks called
Scatternets
, the
networking range of Bluetooth can be extended. Another
reason why Bluetooth is often overlooked is that it offers
little configurability when compared to Wi
-
Fi. Apple offers
some options for zero
-
configuration communications with
Bluetooth, but there is little customization available to the
user, or to the developer writing the software. With some
solid research, Bluetooth networking could become a
powerful networking option for Apples’ mobile computing
devices.


Bluetooth Facts



Bluetooth devices can now play a role of the
“master” and can communicate with up to a maximum
of 7 devices as “slave”. The devices can switch roles, by
agreement, and the slave can become the master at
any time. This group of 8 devices, 1 master and 7
slaves, is called a
Piconet
.



Piconets

can be linked together by “bridges” to form
a larger network called a
Scatternet
.



There is no routing protocol built into Bluetooth, so
there is currently no way for
Piconets

to communicate
with each other within a
Scatternet
.



Bluetooth uses a radio technology called frequency
-
hopping spread spectrum, which chops up the data
and sends it in smaller packets.



The range of a Bluetooth device depends on its
power consumption. High power devices have a range
of approximately 100 meters, but the
iPad

devices
used for this project have a limited reach of 10 meters.


What We
DId



Read

relevant research papers discussing
possibilities of routing protocols, and
Scatternet

formation with Bluetooth.



Researched

the Bluetooth capabilities of the
iPad

device.





Researched

the capabilities of the
GameKit

Framework in the
iPhone

SDK.



Tested

service discovery using Bonjour services in
the
iPhone

SDK.



Developed

“the lost child” algorithm that will allow
a device to lose its connection with its parent device
and then rejoin the
Scatternet

through a nearby
device.



Currently

building a mobile ad
-
hoc Bluetooth
network of Apple devices that will allow for data
transfer between devices.



Currently

developing an
iPad

app that visually
depicts the Bluetooth network using Core Graphics.



Future Work



Apple

needs to expand their Bluetooth capabilities
for future devices.



Once

the Bluetooth SIG (Special Interest Group)
allows more access to the low level details of the
service, there can be a plethora of new networking
possibilities.



A routing protocol implemented within Bluetooth
would allow the formation of a
Scatternet

with file
sharing capabilities.



Improved

bandwidth to speed up data sharing,
making things like video conferencing and messaging
applications more functional.



Developing

large ad
-
hoc networks that can
effectively be used for communication within
individual companies or even on the battlefield.