October 2015
40
E
mbedded
W
ireless
to the administered cellular communications
networks, where the mobile client is passed
on to the next cell by a higher-level manage-
ment entity, no controlling entity is foreseen
for WLAN networks. The client must there-
fore decide for itself at what time it dials
into the next cell and which one it dials into
before the connection breaks off. Almost all
WLAN devices are still based on a widely
passive roaming algorithm: the WLAN cell
is changed only when data is already being
lost and the connection breaks. Understand-
ably, this approach is not suitable for fast and
reliable communication. In this case solution
strategies are mostly based on active roam-
ing achieving switching times below 50ms.
An additional network management server
(WLAN controller) observes the movements
of the clients in its network and actively
and proactively points them to the next cell
(similar to what is done in a cellular phone
network). However, this presupposes an
exchange of proprietary roaming information
between the client and server, as well as their
interoperability. Intelligent client applications
with suitable metrics and application-specific
parameters independently prepare the next
handover, with typically very good results.
This on the other hand increases the indepen-
dence of the network operator.
If highly available and completely seamless
communication is required, several connec-
tions must be maintained simultaneously and
operated using a redundancy protocol. With a
system solution, the application does not need
to worry about fast roaming. The complexity
of relevant algorithms must be hidden behind
an abstract communication interface layer
that is independent of the network technol-
ogy. Only in this way can several applications
benefit from the optimized connectivity at the
same time and without restrictions. As a solu-
tion dedicated external M2M routers and /or
sophisticated internal software middleware
components can be considered.
Experts in the industry are convinced that
seamless communication with standard
wireless technology will also establish itself
for security-relevant applications. The driv-
ing factors for this are: the products can be
used worldwide unlike devices based on
proprietary protocols. Extensive broadband
communication is possible thanks to quick
cell changes using Fast Roaming. Communi-
cation across technology borders facilitates
migration to new technologies because the
existing infrastructure can still be used in the
transitional phase. Dead spots and failures
can be bridged with alternative technologies.
Ultimately, the considerable cost advantage
and the increased independence from the
manufacturer and service provider should be
powerful arguments for investors.
n
Figure 2. Network swapping by means of fast roaming enables continuous and seamless
communication from the mobile client to the control centre and meets the highest demands.
(Source: NetModule AG)
Microchip expands 32-bit MCU family
with integrated floating point unit series
Microchip announces a new series within its
high-performance PIC32MZ family of 32-bit
microcontrollers that features an integrated
hardware Floating Point Unit for high perfor-
mance and lower latency in intensive single
and double-precision maths applications.
ADI: clock jitter attenuator optimizes
JESD204B serial interface functionality
Analog Devices introduced a high-perfor-
mance clock jitter attenuator designed to sup-
port the JESD204B serial interface standard
for connecting high-speed data converters
and FPGAs operating in base station designs.
The JESD204B interface was specifically devel-
oped to address high-data rate system design
needs, and the 3.2-GHz HMC7044 clock jit-
ter attenuator contains functions that support
and enhance the unique capabilities of that
interface standard.
Wibu-Systems: CodeMeter is
ready for Windows 10
With its history of effective cooperation
and Gold OEM partnership with Microsoft,
Wibu-Systems was an early adopter of their
new operating system Windows 10. This has
put Wibu-Systems in a perfect position to
guarantee a smooth migration for the users of
CodeMeter, its all-in-one technology for soft-
ware protection, licensing, and security.
Mouser now stocking Freescale’s PF3000
Power Management Integrated Circuit
Mouser Electronicsis now stocking the
PF3000 Power Management Integrated Cir-
cuit (PMIC) from Freescale Semiconductor.
Developed as a companion device to Frees-
cale’s i.MX 7 series and i.MX 6SoloLite and
i.MX 6SoloX series of application processors,
the PF3000 is a single-chip power manage-
ment solution.
Toshiba expands ApP Lite processor
family for IoT solutions
Toshiba Electronics Europe has announced
the launch of TZ1041MBG, an applica-
tion processor designed for use in wearable
devices such as activity monitoring prod-
ucts, smart watches, bracelet and glasses-type
devices. The new IC is the latest addition to
Toshiba’s ApP Lite TZ1000 family of solutions
for the internet of things.
Renesas: 16- and 32-Mb
Advanced Low Power SRAMs
Renesas Electronics announced the release
of two new series of Advanced Low Power
SRAM (Advanced LP SRAM), the lead-
ing type of low-power-consumption SRAM,
designed to provide enhanced reliability and
longer backup battery life for applications
such as factory automation, industrial equip-
ment, and the smart grid.
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