Mini Course

illnurturedtownvilleΚινητά – Ασύρματες Τεχνολογίες

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

71 εμφανίσεις

1

Mini Course

Programming Context
-
aware Mobile Phones



Thomas Bodin

IT University of Copenhagen


2

Tuesday agenda


General Bluetooth concepts


Definition


Overview


Core specifications


Introduction to BlipNet API

3

General Bluetooth concepts


Definition


A short
-
range wireless communication technology for voice and data.
Bluetooth communicates via a frequency hopping transceiver in the
ISM band. It is based on a low
-
cost short
-
range radio link facilitating
protected ad hoc connections for stationary and mobile
communication.

4

General Bluetooth concepts


Overview


The Bluetooth wireless connectivity technology was originally
envisioned in 1994 by the Swedish phone equipment maker Ericsson
as a way for mobile devices to communicate with each other at short
ranges
--

up to 30 feet, or 10 meters. In 1998, Ericsson, IBM, Intel,
Nokia, and Toshiba formed the Bluetooth Special Interest Group
consortium to develop a royalty
-
free, open specification for short
-
range wireless connectivity. Since then, more than 2000 companies
have joined the Bluetooth SIG, including virtually all manufacturers of
phone, computer, and PDA equipment.

5

General Bluetooth concepts


Core specifications


2.4 GHz ISM Open band


Bluetooth divides the 2.4 GHz frequency band into 79 channels 1
MHz apart (from 2.402 to 2.480 GHz),


The frequency hopping is carried out up to 1600 times a second


10 cm
-
10 meters range (can be extended to 100 m)


8 active devices per piconet (share datarate)


Up to 10 piconets in bubble (full datarate)


1 Megabyte per second gross rate


Bluetooth defines provisions for three low
-
power operating modes in
order to conserve battery life: sniff, park and hold mode

6

General Bluetooth concepts


Core specifications (continued)


802.15 vs. 802.11


While both Bluetooth and IEEE 802.11b are wireless communication
protocols and both operate in the 2.4GHz band, it is important not to
visualize Bluetooth as a replacement for 802.11 wireless LAN technology.


The 802.11b protocol is designed to connect relatively large devices with
lots of power and speed, such as desktops and laptops. Devices
communicate at up to 11 Mbit/sec, at greater distances (up to 300 feet, or
100 meters). By contrast, Bluetooth is designed to connect small devices
like PDAs, mobile phones, and peripherals at slower speeds (1 Mbit/sec),
within a shorter range (30 feet, or 10 meters), which reduces power
requirements.

7

General Bluetooth concepts

RF

BB

LMP

HCI

L2CAP

SDP

RFCOMM

BNEP

TCS

OBEX

PPP

IP

8

General Bluetooth concepts


The radio layer

is the physical wireless connection


The baseband layer

is responsible for controlling and sending
data packets over the radio link


The baseband layer maintains Synchronous Connection
-
Oriented
(SCO) links for voice and Asynchronous Connectionless (ACL) links
for data


The Link Manager Protocol (LMP)

uses the links set up by the
baseband to establish connections and manage piconets.


The Host Controller Interface (HCI)

is the dividing line between
software and hardware.


The Logical Link Control and Adaptation Protocol (L2CAP)

receives application data and adapts it to the Bluetooth format

9

General Bluetooth concepts

Profile

RF

BB

LMP

HCI

L2CAP

SDP

BNEP

TCS

RFCOMM

OBEX

PPP

IP

10

Service Discovery Application Profile

Service

Search

LAN Access Profile,

Object Push Profile

PAN Profile (NAP)

Service

Search

Service

Search

RF

BB

LMP

L2CAP

SDP

BNEP

TCS

RFCOMM

OBEX

PPP

IP

SDAP Profile

11

Serial Port Profile

AT Command

RF

BB

LMP

L2CAP

SDP

BNEP

TCS

RFCOMM

OBEX

PPP

IP

SPP Profile

Serial cable replacement

Basis profile for a series of other profiles

Can be applied directly for data communication

12

Dial
-
Up Networking Profile

DUN
-

GW

DUN Client

Internet

RF

BB

LMP

L2CAP

SDP

BNEP

TCS

RFCOMM

OBEX

PPP

IP

Dial
-
UP Networking Profile

Cellular phone acts a wireless modem for connecting to a
dial
-
up internet access server etc.

13

Object Push Profile

RF

BB

LMP

L2CAP

SDP

BNEP

TCS

RFCOMM

OBEX

PPP

IP

OPP Profile

Buisness Card

Ericsson

Bluetooth Networks

Business Card

Mr Smith

Street X, Town Y

Sound

Image

Video

Game

14

BlipServer


Configuration and management of BlipNodes


Central security handler


Link and session establishment controller


Payload gateway for OBEX and SPP data


Linux and Windows


BlipNet API


BlipServer configuration via BlipManager

15

BlipManager


Graphical configuration and monitoring of the BlipServer and
BlipNodes


Presets for standard configuration


Configuration wizards


Configuration groups


Central controlled security

16

BlipNet API


An Open RMI based Java API


Monitoring of BlipNet (Event and Poll based)


Configuration of dynamic BlipNode settings


Send/Receive objects (OBEX)


Send/Receive serial data


Dynamic Class loading


Inquiry start/stop from API


Friendly Name lookup event