No. 06 December 2011
Get the most out of
Wi-Fi Direct! iWave platforms & solutions, help developers leverage the new personal, portable avatar of Wi-Fi that goes with you, everywhere, anytime
Wi-Fi Direct a new wireless networking
specification introduced by the Wi-Fi Alliance is
based on a set of software protocols that allow
Wi-Fi devices to talk and connect to each other
with or without a Wi-Fi network or hotspot
available. Wi-Fi Direct combines the advantages
of Wi-Fi Ad-hoc connection and Blue Tooth
connection.
Wi-Fi Direct can provide low power secure
communications over fairly long distances for industrial
communications, surveillance equipment, logistics &
freight management, medical patient monitoring and
remote diagnostics.
The key features of Wi-Fi Direct are:
Connecting easy: Wi-Fi Direct devices discover one
another and in some cases the services available. Also
establishing the connection can be as simple as pressing
a button.
Connections are protected by WPA2 security: Wi-
Fi Direct connections will work at typical Wi-Fi ranges
protected by WPA security (with AES or TKIP
Encryption) protocols and including WMM QoS
mechanisms. It supports WPS and WPA2 by default
which many older products using the old broken WEP
encryption don’t.
Connects two or more devices, including legacy
Wi-Fi CERTIFIED gear.
Wi-Fi Direct and Ad-hoc: The ad-hoc networks allow
devices to exchange data with each other without an
access point but implementations almost universally
offer poor security and degraded throughput. The new
method Wi-Fi Direct is a wholesale replacement of the
weak ad-hoc networking mode which is a part of
802.11 but never built into a standardized part of Wi-Fi
nor put through a testing and certification program like
infrastructure mode has. This can make it difficult or
impossible to use the mode between computers running
different OS or even different wireless networking
hardware.
Wi-Fi Direct can also handle quick peer-to-peer sharing
as needed. That’s the kind of thing the 802.11 ad-Hoc
mode has done for years but never with much ease
because Wi-Fi Direct will include mechanisms for
advertising service availability without connecting as
for example you can’t connect wireless printers through
ad-hoc mode while using Wi-Fi Direct you can. One
advantage of the new method is that it can preserve the
full bandwidth of 802.11 and overtake incompatibility
issues that ad-hoc would suffer.
Wi-Fi Direct and Bluetooth : It is said that “Wi-Fi
Direct Could Be the Death of Bluetooth”, as Bluetooth
2.1 reaches a speed of 3 Mbps and Bluetooth 3.0 a speed
of 24 Mbps, Wi-Fi Direct can reach 250 Mbps per
second with 802.11n networks which means Wi-Fi
Direct will be 80 times faster than the common
Bluetooth. Bluetooth is designed with low power
consumption but with a short range approximately 10m
in Class 2 with MPP of 2.5 mW (4 dBm) but Wi-Fi
supports higher ranges with much more power
consumption hence the next move (continued on p.2)
( from p. 1) is to extend wireless power save mode to
all Wi-Fi devices. Almost all notebooks and PCs are
equipped with WLAN cards though it’s not Bluetooth
enabled devices which increases the probability of Wi-Fi
Direct domination. In Bluetooth we have a problem,
changing an encryption key must be done every 23.3
hours (one Bluetooth day) so the Bluetooth host was
required to handle pausing data transfer. With EPR
technique the Bluetooth controller ensures that no
unencrypted data is transferred while they key is
refreshed. Bluetooth 4.0 is using AES 128 bit
encryption while Wi-Fi Direct is using AES 256-bit
encryption.
Mobility & Portability: Wi-Fi Direct-certified devices
connect anytime, anywhere. Users have the ability to
create direct connections with the very first Wi-Fi
Direct-certified device they bring home. For example, a
new laptop certified for Wi-Fi Direct can create direct
connections with the existing legacy Wi-Fi devices in
the user’s home. Wi-Fi Direct devices have features that
allow users to identify available devices and services
before establishing a connection.
Backward compatibility: Wi-Fi Direct is also
designed with backward compatibility in mind, even an
old 802.11b radio could support it. Interoperability
between Wi-Fi Direct devices and legacy devices is a
key element of the specification. Even non-upgraded
devices can join a Wi-Fi Direct network.
Upgradability: Wi-Fi Direct does not require new
hardware to operate so some vendors may offer
software upgrades to existing devices.
Power Management: Efficient use of power is critical
for portable devices. The P2P Specification includes
power management mechanisms that can reduce power
consumption for devices regardless of role within a
Group, while maintaining valuable discovery
capabilities. Wi-Fi Direct devices can support WMM®
Power Save, and the Wi-Fi Direct specification also
defines new power saving mechanisms-- Opportunistic
and Notice of absence.
The key mechanisms of Wi-Fi Direct are:
Device Discovery: The objective of P2P (peer to peer)
Device Discovery is to find P2P Devices and quickly
determine the P2P Device to which a connection will be
attempted. P2P Device Discovery consists of two major
phases: Scan and Find
Service Discovery: The Service Discovery procedure
is an optional frame exchange that may be performed at
any time to any discovered P2P Device, for example
following a successful Device Discovery procedure prior
to group formation. This procedure can be used to
determine compatibility information on the services
offered by a P2P Device.
Group Formation ( Client Discovery and Invitation) :
A P2P Device may use the Group Formation Procedure
to form a new P2P Group. Group Formation is used to
determine which device shall be the P2P Group Owner
(appears to be an access point to other legacy Wi-Fi
Devices.)
iWave Wi-Fi Direct expertise includes Wi-Fi Direct
support for the iMX51 CPU Platform (iW-Rainbow-
G8D board). iMX53 CPU Platform (iW-Rainbow-G11D
board) support is under development. We currently
support Wi-Fi Direct with features like WPS,
WPA/WPA2 Authentication, AES /TKIP Encryption.
iWave can provide Wi-Fi Direct Linux source code and
support for building WLAN driver. We also support Wi-
Fi Direct driver in Vx works, ITRON, Android and
other operating systems.
A dedicated team at iWave, for Wi-Fi Direct research
and development is poised to introduce many more
solutions that will help OEMs and product developers
leverage this exciting new extension to Wireless
networking, providing users a single-technology
solution to transfer content and share applications
quickly and easily among wired and wireless devices.
- Dhanya J.R.
iWave’s
iW-Rugged Handheld:
A computing companion for extreme environments
iWave’s Rugged Handheld is your solution
to the challenge of operating a computing
device in harsh outdoor environments for
military, aeronautical or industrial
applications.
The iW-Rugged handheld is packaged in tough,
rugged shell made of aluminium alloy and
meets the Military Standard 810E for drop,
vibration, water and dust at temperatures
between -20 to +70 degree centigrade, as well as
the 461E MilSpec for EMI/EMC.
This tough buddy has an ARM based Marvell
PXA270 processor, working at 520 MHz and is
rich in communication peripherals and
memory/storage interfaces. The Rugged PDA has
a unique modular design that consists of the core
computer which has a SD Card slot, a serial port,
audio in/out, and an internal Li-ion battery (7.4V
– 1.7 Ah).The unit is completely sealed, and can
be used in rain. Even more, the handheld packs a
seamlessly integrated resistive touch screen to
ensure input and control flexibility for
applications like GPS navigation and
communication in general.
This integrated modular design saves Time to
Market and design cost by providing
customization for wide spectrum of applications.
For more information, visit
http://www.iwavesystems.com/iW-
RuggedPDA.htm
iWave’s Singapore saga is one year old!
iWave’s Singapore family
In 2010, iWave and local partner Spyro Technology
(www.spyrotechnology.com/) won a design service
contract from a key customer in Singapore. For iWave
and for the eight engineers who have made Singapore
their home for over a year now, this was breakthrough
and vindication of the way we work and deliver. We are
happy to announce the renewal of our Singapore
contract in recognition of the good performance from
our engineers. For many of our engineers, it was their
first taste of the island-city and a year down the road,
they have happy memories to share:
For Siddiq, the clean and green multi-culture country
with fast growing economy is what impresses most. “
It’s so easy to adopt for any kind of people. My mother
tongue is Tamil and it is one of the Singapore's national
languages. There are many Tamil speaking people,
schools, and it is also used in MRT stations too”, he
says.
Gomathy has no doubts: “No noise pollution or air
pollution!”, she exclaims, adding, “Singaporeans are so
patient. Everywhere you can see people standing in
queue …in restaurants, bus stops, ATM, etc. Even
when people are in a hurry, they will wait for the green
light signal before they move on”.
Saravanan has done all the touristy things and says:
“I recommend Sentosa for a great day out with the
family. Underwater world creates an environment as if
you are walking under the sea. You will see very rare
sea-life species and learn about the water animals.
Songs of the sea is a unique water show in which you
can see images being projected into a screen make up of
splashing water..”
No slackers when it comes to the professional side,
iWave’s Singapore team has a few notes to share: “Stick
with the performance and standard criteria. Strictly
following the organization work processes. Learning
any technology/domain very deeply. Singaporeans are
multi talented technical people and it is always a
pleasure to work with them!”
Meet iWave engineers and executives at these international shows:
http://www.dspdesigncontest.com/Technology_Day/Tech
_Registration.aspx
http://www.embedded-world.de/en/
Missed some of our product announcements and tech
briefs in earlier issues of Crest? Here’s a checklist of
key topics and links to past issues:
Crest November 2011:
iWave's FPGA IP core: A hedge against x86 obsolescence http://www.iwavesystems.com/IPs/Crest_5_November.pdf
Crest October 2011:
iWave’s Unified learning kit with TI OMAP3530: http://www.iwavesystems.com/IPs/iWave_Crest%204%20October.pdf
Crest September 2001:
Industry-first solution for Freescale i.MX508 processor and applications centred around Electronic Paper Displays
http://www.iwavesystems.com/IPs/Crest%203_September_Issue.pdf
Crest August 2011: iWave SOM for Freescale’s i.MX53 processor. Application: x86 FPGA core used for air traffic control
systems. iWave’s solutions on Intel Stellarton FPGA-processor.
http://www.iwavesystems.com/IPs/iWave_Crest%202%20August%20Edition.pdf
Crest July 2011:
iWave’s RainboW SOM based on FreeScale’s i.MX51 processor http://www.iwavesystems.com/IPs/iWave%20Crest%20July,%202011.pdf
www.iwavesystems.com [email protected]
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