15 research outputs found
Reliable Reporting for Massive M2M Communications with Periodic Resource Pooling
This letter considers a wireless M2M communication scenario with a massive
number of M2M devices. Each device needs to send its reports within a given
deadline and with certain reliability, e. g. 99.99%. A pool of resources
available to all M2M devices is periodically available for transmission. The
number of transmissions required by an M2M device within the pool is random due
to two reasons - random number of arrived reports since the last reporting
opportunity and requests for retransmission due to random channel errors. We
show how to dimension the pool of M2M-dedicated resources in order to guarantee
the desired reliability of the report delivery within the deadline. The fact
that the pool of resources is used by a massive number of devices allows to
base the dimensioning on the central limit theorem. The results are interpreted
in the context of LTE, but they are applicable to any M2M communication system.Comment: Submitted to journa
Sparse Message Passing Based Preamble Estimation for Crowded M2M Communications
Due to the massive number of devices in the M2M communication era, new
challenges have been brought to the existing random-access (RA) mechanism, such
as severe preamble collisions and resource block (RB) wastes. To address these
problems, a novel sparse message passing (SMP) algorithm is proposed, based on
a factor graph on which Bernoulli messages are updated. The SMP enables an
accurate estimation on the activity of the devices and the identity of the
preamble chosen by each active device. Aided by the estimation, the RB
efficiency for the uplink data transmission can be improved, especially among
the collided devices. In addition, an analytical tool is derived to analyze the
iterative evolution and convergence of the SMP algorithm. Finally, numerical
simulations are provided to verify the validity of our analytical results and
the significant improvement of the proposed SMP on estimation error rate even
when preamble collision occurs.Comment: submitted to ICC 2018 with 6 pages and 4 figure
Code-Expanded Random Access for Machine-Type Communications
The random access methods used for support of machine-type communications
(MTC) in current cellular standards are derivatives of traditional framed
slotted ALOHA and therefore do not support high user loads efficiently.
Motivated by the random access method employed in LTE, we propose a novel
approach that is able to sustain a wide random access load range, while
preserving the physical layer unchanged and incurring minor changes in the
medium access control layer. The proposed scheme increases the amount of
available contention resources, without resorting to the increase of system
resources, such as contention sub-frames and preambles. This increase is
accomplished by expanding the contention space to the code domain, through the
creation of random access codewords. Specifically, in the proposed scheme,
users perform random access by transmitting one or none of the available LTE
orthogonal preambles in multiple random access sub-frames, thus creating access
codewords that are used for contention. In this way, for the same number of
random access sub-frames and orthogonal preambles, the amount of available
contention resources is drastically increased, enabling the support of an
increased number of MTC users. We present the framework and analysis of the
proposed code-expanded random access method and show that our approach supports
load regions that are beyond the reach of current systems.Comment: 6 Pages, 7 figures, This paper has been submitted to GC'12 Workshop:
Second International Workshop on Machine-to-Machine Communications 'Key' to
the Future Internet of Thing
Hey! I Have Something for You: Paging Cycle Based Random Access for LTE-A
The surge of M2M devices imposes new challenges for the current cellular network architecture, especially in radio access networks. One of the key issues is that the M2M traffic, characterized by small data and massive connection requests, makes significant collisions and congestion during network access via the random access (RA) procedure. To resolve this problem, in this paper, we propose a paging cycle-based protocol to facilitate the random access procedure in LTE-A. The high-level idea of our design is to leverage a UE's paging cycle as a hint to preassign RA preambles so that UEs can avoid preamble collisions at the first place. Our rpHint has two modes: (1) collision-free paging, which completely prevents cross-collision between paged user equipment (UEs) and random access UEs, and (2) collision-avoidance paging, which alleviates cross-collision. Moreover, we formulate a mathematical model to derive the optimal paging ratio that maximizes the expected number of successful UEs. This analysis also allows us to adapt dynamically to the better one between the two modes. We show via extensive simulations that our design increases the number of successful UEs in an RA procedure by more than 3× as compared to the legacy RA scheme of the LTE
On Supporting Small M2M Data Transmissions in LTE/LTE-A Networks
In Machine-to-Machine (M2M) applications, devices monitor events (e.g., temperature, inventory
level), which is relayed through a communication network infrastructure (e.g. Internet, LTE) to an
application (software program running on a server connected to the Internet), that translates the
monitored event into some meaningful information to be able to take collaborative decisions with
limited or no human intervention.
With the availability of IPv6 address, it is possible to interconnect everything in this universe.
By using the concept of interconnecting things, several applications can be envisioned to make the
world smarter. Internet of Things (IoT) is a paradigm whose aim is to implement the concept of
interconnection of everything by using all possible technologies and others means. M2M communica-
tion is one of the components of Internet of Things (IoT) whose goal is to make the communication
smooth and seamless between any two networking enabled devices. According to the researchers by
the end of 2014, 1.5 billion devices and by the end of 2020, 20 billion devices will be part of M2M
communication
Signaling Congestion Control Mechanisms for Supporting Machine-To-Machine Communications in 4G LTE Cellular Networks
Typically, in Machine-to-Machine (M2M) communication system, an M2M device (sensor, meter,
etc.) captures an event (pressure, inventory level, etc.), which is relayed through a communication
network (wireless, wired or hybrid, cellular) to an application (software program), that translates
the captured event into meaningful information without any human intervention. Based on this
concept, several noble applications have been developed such as environment monitoring, smart
grid, e-healthcare, and fleet management which will affect various aspects of our life