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leverage LTE Direct to benefit from
this space, and understanding key
platform considerations for an LTE
Direct deployment, which is currently
being standardized in 3GPP as part of
Release 12.
VoLTE (Voice Over LTE)
Current LTE M2M devices are classified
not only by 3GPP category standards
but also single or multi modes. A multi-
mode LTE device supports fallback to
3G and even 2G when LTE coverage
become weak or non-existent, while
single-mode devices support LTE only.
The voice call feature in a multi-mode
device can be supported by falling
back to GSM/WCDMA network service,
then establishing the call.
In LTE only mode (or multi-mode
devices implementing VoLTE), the call
is established on LTE based on IMS
(IP Mobile System) system network
defined in 3GPP.
VoIP global status is growing fast,
together with the new LTE network
implementation. The current status is
as follows:
111 operators are investing in
VoLTE in 52 countries (deployments,
trials, studies)
30 operators commercially launched
VoLTE HD voice in 21 countries
LTE Category 1
The LTE Category 1 specifically
addresses the needs of M2M device
makers for an especially low cost
solution. Cat 1 provides up to 10 Mbps
in downlink and has been part of the
earliest 3GPP LTE specifications, in
Release 8. Cellular operators can
deploy LTE Cat 1 device support with
no need for new network equipment
or major upgrades, allowing them
to manage their networks more
efficiently by not allocating excessive
resources to devices that require low
throughput. Cat 1 provides meaningful
power and at a lower cost than their
3G and 4G counterparts. Cat 0 will
mean big changes for the operators
in terms of the infrastructure and in
the way they manage and allocate
spectrum. LTE-M (up to 200 Kbps)
is associated with the forthcoming
Release-13 standard.
LTE-M will support the following
capabilities:
Reduced device bandwidth of 1.4
MHz in downlink and uplink
Reduced maximum transmit power
of 20 dBm
Reduced support for downlink
transmission modes
Further device processing
relaxations are under consideration
PSM Power-Saving Mode
In 3GPP Release 12, a device power-
saving mode (PSM) was introduced,
enabling a significant improvement
in device battery life. If the device
supports PSM, it asks the network
for a certain active timer value
during an attach or tracking area
update procedure; the active timer
determines the duration for which
Figure 1
Figure 2
cost and power reductions compared
to today’s Cat 3 (up to 100Mbps) and
Cat 4 (up to 150Mbps).
A few networks are already configured
to allow Cat 1 devices, and more are
expected to follow in the next few
months. Now that LTE Cat 1 chipsets
are available, we will see Cat 1 devices
ramping up steadily in 2016.
Release 13 - LTE-M (MTC)
Category 0 (up to 1 Mbps) is still
being defined in 3GPP’s Release
12 LTE standard. 3GPP Release 12
introduces Cat 0 for the first time and
defines features for M2M, specifically
for what the 3GPP calls Machine Type
Communications, or MTC. When it
becomes fully defined, it will describe
significant reductions in complexity
and address the need for battery-
powered devices consuming far less
Figure 3
48 l New-Tech Magazine Europe