This paper provides an overview of the Internet of Things (IoT) with emphasis on enabling technologies, protocols, and application issues. The IoT is enabled by the latest developments in RFID, smart sensors, communication technologies, and Internet protocols. The basic premise is to have smart sensors collaborate directly without human involvement to deliver a new class of applications. The current revolution in Internet, mobile, and machine-to-machine (M2M) technologies can be seen as the first phase of the IoT. In the coming years, the IoT is expected to bridge diverse technologies to enable new applications by connecting physical objects together in support of intelligent decision making. This paper starts by providing a horizontal overview of the IoT. Then, we give an overview of some technical details that pertain to the IoT enabling technologies, protocols, and applications. Compared to other survey papers in the field, our objective is to provide a more thorough summary of the most relevant protocols and application issues to enable researchers and application developers to get up to speed quickly on how the different protocols fit together to deliver desired functionalities without having to go through RFCs and the standards specifications. We also provide an overview of some of the key IoT challenges presented in the recent literature and provide a summary of related research work. Moreover, we explore the relation between the IoT and other emerging technologies including big data analytics and cloud and fog computing. We also present the need for better horizontal integration among IoT services. Finally, we present detailed service use-cases to illustrate how the different protocols presented in the paper fit together to deliver desired IoT services.

Internet of Things: A Survey on Enabling Technologies, Protocols, and Applications

Millimeter wave (mmWave) signals experience orders-of-magnitude more pathloss than the microwave signals currently used in most wireless applications and all cellular systems. MmWave systems must therefore leverage large antenna arrays, made possible by the decrease in wavelength, to combat pathloss with beamforming gain. Beamforming with multiple data streams, known as precoding, can be used to further improve mmWave spectral efficiency. Both beamforming and precoding are done digitally at baseband in traditional multi-antenna systems. The high cost and power consumption of mixed-signal devices in mmWave systems, however, make analog processing in the RF domain more attractive. This hardware limitation restricts the feasible set of precoders and combiners that can be applied by practical mmWave transceivers. In this paper, we consider transmit precoding and receiver combining in mmWave systems with large antenna arrays. We exploit the spatial structure of mmWave channels to formulate the precoding/combining problem as a sparse reconstruction problem. Using the principle of basis pursuit, we develop algorithms that accurately approximate optimal unconstrained precoders and combiners such that they can be implemented in low-cost RF hardware. We present numerical results on the performance of the proposed algorithms and show that they allow mmWave systems to approach their unconstrained performance limits, even when transceiver hardware constraints are considered.

Spatially Sparse Precoding in Millimeter Wave MIMO Systems

Millimeter wave (mmWave) holds promise as a carrier frequency for fifth generation cellular networks. Because mmWave signals are sensitive to blockage, prior models for cellular networks operated in the ultra high frequency (UHF) band do not apply to analyze mmWave cellular networks directly. Leveraging concepts from stochastic geometry, this paper proposes a general framework to evaluate the coverage and rate performance in mmWave cellular networks. Using a distance-dependent line-of-site (LOS) probability function, the locations of the LOS and non-LOS base stations are modeled as two independent non-homogeneous Poisson point processes, to which different path loss laws are applied. Based on the proposed framework, expressions for the signal-to-noise-and-interference ratio (SINR) and rate coverage probability are derived. The mmWave coverage and rate performance are examined as a function of the antenna geometry and base station density. The case of dense networks is further analyzed by applying a simplified system model, in which the LOS region of a user is approximated as a fixed LOS ball. The results show that dense mmWave networks can achieve comparable coverage and much higher data rates than conventional UHF cellular systems, despite the presence of blockages. The results suggest that the cell size to achieve the optimal SINR scales with the average size of the area that is LOS to a user.

Coverage and Rate Analysis for Millimeter-Wave Cellular Networks

LTE Release 8 is one of the primary broadband technologies based on OFDM, which is currently being commercialized. LTE Release 8, which is mainly deployed in a macro/microcell layout, provides improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operation and seamless integration with existing systems. LTE-Advanced (also known as LTE Release 10) significantly enhances the existing LTE Release 8 and supports much higher peak rates, higher throughput and coverage, and lower latencies, resulting in a better user experience. Additionally, LTE Release 10 will support heterogeneous deployments where low-power nodes comprising picocells, femtocells, relays, remote radio heads, and so on are placed in a macrocell layout. The LTE-Advanced features enable one to meet or exceed IMT-Advanced requirements. It may also be noted that LTE Release 9 provides some minor enhancement to LTE Release 8 with respect to the air interface, and includes features like dual-layer beamforming and time-difference- of-arrival-based location techniques. In this article an overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed. This includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, uplink spatial multiplexing including extension to four-layer MIMO, and heterogeneous networks with emphasis on Type 1 and Type 2 relays. Finally, the performance of LTEAdvanced using IMT-A scenarios is presented and compared against IMT-A targets for full buffer and bursty traffic model.

LTE-advanced: next-generation wireless broadband technology [Invited Paper]

Due to the broadcast nature of radio propagation, the wireless air interface is open and accessible to both authorized and illegitimate users. This completely differs from a wired network, where communicating devices are physically connected through cables and a node without direct association is unable to access the network for illicit activities. The open communications environment makes wireless transmissions more vulnerable than wired communications to malicious attacks, including both the passive eavesdropping for data interception and the active jamming for disrupting legitimate transmissions. Therefore, this paper is motivated to examine the security vulnerabilities and threats imposed by the inherent open nature of wireless communications and to devise efficient defense mechanisms for improving the wireless network security. We first summarize the security requirements of wireless networks, including their authenticity, confidentiality, integrity, and availability issues. Next, a comprehensive overview of security attacks encountered in wireless networks is presented in view of the network protocol architecture, where the potential security threats are discussed at each protocol layer. We also provide a survey of the existing security protocols and algorithms that are adopted in the existing wireless network standards, such as the Bluetooth, Wi-Fi, WiMAX, and the long-term evolution (LTE) systems. Then, we discuss the state of the art in physical-layer security, which is an emerging technique of securing the open communications environment against eavesdropping attacks at the physical layer. Several physical-layer security techniques are reviewed and compared, including information-theoretic security, artificial-noise-aided security, security-oriented beamforming, diversity-assisted security, and physical-layer key generation approaches. Since a jammer emitting radio signals can readily interfere with the legitimate wireless users, we also introduce the family of various jamming attacks and their countermeasures, including the constant jammer, intermittent jammer, reactive jammer, adaptive jammer, and intelligent jammer. Additionally, we discuss the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Finally, some technical challenges which remain unresolved at the time of writing are summarized and the future trends in wireless security are discussed.

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A Survey on Wireless Security: Technical Challenges, Recent Advances, and Future Trends

A system and method for uplink control signaling in a communication system includes a step of transmitting ( 200 ) the uplink control signaling in a frequency resource of the communication system reserved for random access. In particular, this step ( 200 ) can include allowing ( 202 ) the Physical Uplink Control Channel (PUCCH) to coexist with the Physical Random Access CHannel (PRACH) and transmitting ( 204 ) only channels which do not require Acknowledged/Negative Acknowledged (ACK/NACK) transmission.

Uplink control signaling in a communication system

A communication system is provided that dynamically allocates power to a Multimedia Broadcast/Multicast Service (an MBMS service). In response to determining to establish a Point-to-Multipoint (PTM) communication channel to multiple user equipment (UEs), the communication service assigns the PTM communication channel to the MBMS service, determines a power requirement associated with each user equipment (UE) of the multiple UEs based on a handover quality measurement associated with the UE to produce multiple power requirements, and allocates a power level to the PTM communication channel based on the multiple power requirements. The communication system further dynamically adjusts the allocated power based on a handover quality measurement associated with a UE of the multiple UEs that is received during provision of the MBMS service.

Method and apparatus for dynamic power allocation to a multimedia broadcast/multicast service

In a mobile telecommunication system (10), a number of user equipments (40-45) may receive multimedia broadcast multicast services. The method for power allocation and user assignment for MBMS services determines any number (K) of user equipments which may be served without complete cell area coverage (78). For more than K user equipments (40-45) requesting MBMS services, dedicated channels are assigned (84). For user equipments requesting MBMS service during a broadcast, such user equipment is assigned to the channel (broadcast or dedicated) with the lower power requirement, if power is available. If the user is assigned to the broadcast channel, and power is available, power of the broadcast channel is adjusted (108). Otherwise, the power of the broadcast channel is increased and no further power is indicated as being available (112).

Power allocation method for multicast services

A system and method for uplink power control for aggregated channels in a communication network includes a step 300 of defining power scaling parameters to be used to derive power scaling factors to be applied to associated aggregated uplink channels. A next step 302 includes providing the power scaling parameters to user equipment. A next step 304 includes applying power scaling factors derived from the power scaling parameters to the associated aggregated uplink channels when the user equipment will exceed a maximum transmit power.

Uplink power control for channel aggregation in a communication network

A scheduler capable of operating in an Orthogonal Frequency Division Multiplexing communication system schedules a control channel for a user equipment by determining a channel quality metric associated with the user equipment, calculating a target control channel element quality metric, determining a control channel element utilization rate, wherein the control channel element utilization rate a past rate of utilization of control channel elements, and selecting a control channel element aggregation level for the control channel based on the channel quality metric, the target control channel element quality metric, and the control channel element utilization rate. The scheduler then allocates control channel elements to the control channel based on the selected control channel element aggregation level. The scheduler further may steal power from one or more unused control channel elements and assign the stolen power to control channel elements assigned to the control channel.

Rapeepat Ratasuk

Papers

Uplink control signaling in a communication system

Method and apparatus for dynamic power allocation to a multimedia broadcast/multicast service

Power allocation method for multicast services

Uplink power control for channel aggregation in a communication network

Method and apparatus for scheduling a controlchannel in an orthogonal frequency division multiplexing communication system