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This poster presents the design, development and test results of an energy consumption analysis module developed over ns3 Millimeter Wave (mmWave) communication for analyzing power consumption for 5G New Radio (NR) User Equipment (UE) during both continuous and discontinuous packet receptions. This module is important to analyze and explore the energy consumption behavior of the 5G communication protocols under the NR technology. The developed module includes the complete Radio Resource Control (RRC) state machine for 5G NR recommended by 3GPP Specification 38.840. To the best of our knowledge, the designed module is the first of its kind that provides a comprehensive energy analysis for the 5G NR UEs over mmWave communication.

Communication system is evolving day by day and now entire globe communication is based on internet. Office work, academic activities in engineering field, business, banking system, government offices and different digital gazettes are performing regular processes using internet. So, data traffic volume goes on increasing exponentially and needs high capacity networks. 5th Generation (5G) networks are optimistic system to accommodate requirements of increasing demand. Complexity and challenges will also increase as system grows. Hence imminent insights and predictions are important to govern the 5G system systematically and avoid disasters in the coming days. Computational intelligence techniques are required to forecast solutions to run the system smoothly. Fuzzy logic controller is one such system to handle the dynamics and the non-linearity processes in 5G network. Authors propose novel fuzzy control algorithm to allocate the resources for User Equipment (UE) in 5G wireless network. Nowadays in the internet, multimedia data is the preferred traffic and that has contributed more to the volume of data. So Real time (RT) and Non Real time (NRT) types of requests are considered in this research. Radio Resource Control (RRC) connection management and communication protocol is used by wireless base station gNodeB (gNB) of 5G networks. The function of RRC is controlled by proposed fuzzy control algorithm. Fuzzy rules are designed, applied and analyzed for different combinations of inputs and outputs. Proposed RT First queue scheduling is used to process the RT and NRT requests. It is compared with First Come First Serve (FCFS) scheduling. RT First queue scheduling shows average response time 40% less than FCFS.

This paper describes the implementation of 5G New Radio (NR) network monitoring equipment using software defined radio (SDR). Network operation monitoring is performed based on the radio resource control (RRC) message and control channel analysis. The proposed measurement equipment is capable of synchronization with available network and performing control channel information interpretation and analysis. In order to validate the operation of the proposed monitoring equipment, the measurement results have been compared with the commercially available diagnostic monitor tool, which can directly access data from a smartphone chipset. The performed measurements validate correct operation of the proposed measurement equipment.

The Fifth-Generation (5G) cellular mobile networks are expected to support three service categories and one of them is Ultra-reliable low latency communication (URRLC). For URLLC type of services, 3GPP has strict performance requirements of low latency and high reliability. According to ITU-R M.2410-0 and 3GPP Technical Specification (TS) 38.913, error rate should be lower than 1 packet loss in 105 packets and latencies should be lower than 0.5ms uplink/downlink for URLLC. To ensure such high reliability, packet retransmissions or packet duplication may be performed which will incorporate additional delays to the communication. Hence, there are multiple open research problems for achieving very low latency along with high reliability for URLLC. To the best of our knowledge, this paper for first time solved one of the research problems, by proposing a new call flow where 5G Radio Resource Control (RRC) Release message is to be enhanced such that accessing network for Mobile Originating (MO) call/data in ultra-reliable low latency devices will achieve a reliability with lower than error rate of 1 packet loss in 105 packets along with shorter latency than existing art. Through extensive experiments and simulation, the proposed idea, reduced error rate below than 0.0001% with improved latency as success rate increased to 99.99% during initial access than existing method.

To meet the low latency demand of 5G Ultra-Reliable and Low Latency Communications (URLLC), International Telecommunication Union (ITU) specifically required the control plane (CP) latency, i.e., the time for user equipment (UE) to change from Radio Resource Control (RRC)_IDLE state to RRC_CONNECTED state, to be less than 20 ms and also encouraged proposals to further reduce it to less than 10 ms. To fulfill the CP latency target, a novel random access procedure (RAP) design is introduced, in which the message exchange procedure is simplified and the demodulation reference signal (DMRS) is used to represent the UE ID. Simulation results show that each UE completes the RAP in one iteration of the proposed RAP due to its collision-free property. Specifically, with the pro-posed RAP, at least 85% of URLLC users complete the RAP within 10 ms in the worst case.

In long-term evolution-advanced (LTE-A) network, the third-generation partnership project has proposed machine-type communications (MTC) as a new paradigm where devices transfer data among themselves with limited human interaction. For devices in MTC, power saving has become an important issue because many devices are powered by battery. In LTE-A network, the standard power saving mechanism, called discontinuous reception (DRX), is designed for normal mobile users, not for MTC devices. In this paper, we propose an optimistic DRX (ODRX) mechanism to be suitable for MTC devices. ODRX considers the radio resource control connection release and re-establishment to save more power. We also introduce the optimistic flag to allow longer sleep periods. Analytical and simulation models are proposed to investigate the performance of ODRX, and ODRX is then compared with the standard DRX and dynamic DRX (DDRX) through simulation experiments. The results show that ODRX outperforms standard DRX and DDRX by gaining significant extra power saving with little extra wake up latency. We also propose guidelines to configure ODRX parameters.

In Fifth Generation (5G), wireless cellular networks, smartphone battery efficiency, and optimal utilization of power have become a matter of utmost importance. Battery and power are an area of significant challenges considering smartphones these days are equipped with advanced technological network features and systems. These features require much simultaneous power to make decisions and to transfer information between devices and network to provide best the user experience. Furthermore, to meet the demands of increased data capacity, data rate, and to provide the best quality of service, there is a need to adopt energy-efficient architectures. This paper presents system-level architectural changes on both User Equipment (UE) and Network elements along with a proposal to modify control signaling as part of Radio Resource Control messages using smartphone battery level. Additionally, we presented real-world 5G mmWave field results, showing impacts on device battery life in varying RF conditions and proposed methods to allocate optimal network resources and improve the energy efficiency by modifying radio layer parameters between devices and base stations. Without these proposed architecture level and system-level algorithm changes, realizing optimal and consistent 5G speeds will be near impossible.

The interface between the Radio Access Network and Core Network is kept for Radio Resource Control (RRC) Inactive relative to RRC Idle, and the initial access should be conducted for inactive user equipments (UEs) to reduce the delay of link connection when inactive UEs switch to active. However, due to less interaction information between inactive UEs and transmission and reception points (TRPs), it is necessary to conduct initial access by beam sweeping rather than refined beam alignment. In this paper, an effective uplink multi-beam initial access scheme for inactive UEs in mmWave networks is proposed, where uplink beam sweeping and fast beam recovery is considered. Due to the application of digital beamforming technology and considering that TRP scanning beam number is more than that of UE scanning beams, the delay of uplink based beam sweeping is significantly reduced in the proposed initial access scheme, compared with the traditional downlink based beam sweeping. Furthermore, when the serving beam pair is blocked or not available, fast beam recovery would be conducted by using backup beam pair, where the cases that the backup beam pair and serving beam pair belonging to the same TRP or different TRPs are considered. Simulation results present the effect of density of TRPs, beam sweeping cycle and UE speed on outage probability and average rate after inactive UEs switching to active, and verify initial access performance gain of the proposed initial access scheme.

Currently the 3rd generation partnership project (3GPP) is studying how user equipment power saving can be improved for the fifth generation New Radio technology. To accomplish this objective, a power model has been developed for evaluation of power saving schemes related to Radio Resource Management in Radio Resource Control (RRC) Connected mode among other topics. In this work, we examine the power saving potential in RRC Connected mode using a single-user numerical simulation tool employing the user equipment power model. We demonstrate that the use of short Discontinuous Reception (DRX) can provide 26 % energy saving and 74 % latency reduction as compared to the long DRX-only baseline. Furthermore, the simulation results, based on the user equipment power model, show that four Physical Downlink Control Channel (PDCCH) optimization monitoring schemes: cross-slot scheduling, reduced blind PDCCH decoding candidate set, wake-up signaling and go-to-sleep signaling, may further reduce the energy consumption 17-20 % at the cost of a latency increase and potentially lower overall network performance.

As 5G high-speed mobile communications developing rapidly, services and contents that people get from the Internet have been enriched significantly, which necessitates the user equipment (UE) to have least power consumption, reduced latency, enhanced lifetime and better QoS. However, the tail energy of LTE interface on UE leads to low energy efficiency which is caused by applying fixed Radio Resource Control (RRC) inactivity timer. In this paper, we propose a novel approach to eliminate the tail whenever possible and improve the user equipment power efficiency. We design a self-adaptive tool to optimize the LTE RRC inactivity timer for individual users based on user model. Firstly, The tool collects runtime network information from cellular networks and uses machine learning method to predict the session length. Then it adjusts inactivity timer dynamically based on the predicted session length. In addition, we propose an enhanced RRC protocol to support our proposed tool. To demonstrate the effectiveness of our energy-saving tool, we applied it on commercial off-the-shelf phones. Simulation results show the proposed tool can reduce the energy consumption of smart-phone by 27-33.5%.

In order to efficiently accommodate heavy wireless traffic in the 5G/IoT era, an attractive approach is to utilize wireless LAN (WLAN). To enhance the WLAN system capacity, it is considered to acquire and utilize multi radio interface in the access points (APs). However, the conventional radio resource control techniques do not take into account variety of multi radio interface, the effect of multi radio interface is no sufficiently exhibited. In this paper, we propose a novel multi radio interface control scheme based on simultaneous transmission technique of the new generation wireless LAN (802.11ax). The proposed scheme uses standard WLAN information of each station (STA) to control the setting of each radio interface of the APs and connection to the STAs. The effectiveness of the proposal is clarified by computer simulation.

In the Internet of Things (IoT), it is desirable that every IoT device will be capable to communicate with the network at any time. Among various technologies to enable network connectivity, the Long Term Evolution (LTE) is by far the most ubiquitous technology to provide large coverage of IoT devices. Machine-Type Communications (MTC) is seen as a major service in the next generation cellular mobile networks for IoT. However, the predicted large number of MTC devices will overload the Radio Access Network (RAN), with impact on non-MTC devices. In this work, we propose a design of a RAN overload control mechanism based in clustering that is exclusively engineered for delay-tolerant MTC devices. The proposed solution is intended for delay-tolerant MTC devices with a Radio Resource Control (RRC) context (have a Cell Radio Network Temporary Identity (C-RNTI)) but without being synchronized with the network. By simulation, we show that the proposed scheme leads to acceptable collision levels, besides ameliorating the energy efficiency.

A user equipment (UE) with Dual Subscriber-identity-module (SIM) Dual Standby (DSDS) feature can connect to two network operators, such as, each SIM is associated with one operator and with one Protocol Software Stack (PSS) while both the SIMs share same Radio Frequency Integrated Circuit (RFIC). UE schedules SIM-1 to communicate with Operator-1 and at the same time SIM-2 remains standby and vice versa. The ongoing data session with Operator-1, through SIM-1 is interrupted while the UE's RFIC tunes away to attend a higher priority signaling through SIM-2 to Operator-2. This tune away procedure of RFIC results in allocated Physical Channel Resource (PCR) wastage at Operator-1 for SIM-1 during the tune away period. After the end of tune away at SIM-1, it further more suffers from low PCR allocation from Operator-1, because of no response from SIM-1 during tune away period. To overcome the above challenges, to the best of our knowledge, for first time this paper proposed Signaling indication from UE to network for RFIC tune away event to reduce network PCR wastage. This signaling is done by: (a) Radio Resource Control (RRC) layer (b) Medium Access Control (MAC) layer (c) Layer 1 (L1). Each of the above-mentioned signaling has particular level of latency and reliability. We propose to apply above-mentioned signaling in scenario specific manner to address all possible tune away events. Through extensive simulation derived from mathematical modelling and measurements obtained from test bed with commercial DSDS UEs, the results reveal an improvement in overall PCR utilization for an operator and increase in UE admission by up to 30% in comparison with current DSDS solutions.

Most practical energy-saving mechanisms for a modem rely on a packet transmission delaying technique where the smartphone attempts to reduce the energy consumption of the modem by delaying transmissions of delay-tolerant packets and piggybacking them onto later packets. However, unconditional packet transmission delaying may lead to unanticipated energy loss at the modem since the exact radio resource control state of the modem is not considered. In order to address this problem, we propose a mechanism that selectively delays the packet transmissions only if such delays are expected to achieve energy savings. Our mechanism consists of three key components, which are deferrable packet identifier, pattern-based next packet transmission predictor and packet transmission time designator. In order to demonstrate the effectiveness, we have implemented all three components into Android 4.4 KitKat running on a Google Nexus 5 smartphone and then performed extensive experiments. Our experiments show that the proposed mechanism reduces the energy consumption of an LTE modem by up to 22.5 percent when compared to that of a legacy LTE modem

Frequent handovers (HOs) in dense small cell deployment scenarios could lead to a dramatic\ud increase in signalling overhead. This suggests a paradigm shift towards a signalling conscious cellular\ud architecture with intelligent mobility management. In this direction, a futuristic radio access network\ud with a logical separation between control and data planes has been proposed in research community. It\ud aims to overcome limitations of the conventional architecture by providing high data rate services under\ud the umbrella of a coverage layer in a dual connection mode. This approach enables signalling efficient\ud HO procedures, since the control plane remains unchanged when the users move within the footprint of\ud the same umbrella. Considering this configuration, we propose a core-network efficient radio resource\ud control (RRC) signalling scheme for active state HO and develop an analytical framework to evaluate its\ud signalling load as a function of network density, user mobility and session characteristics. In addition,\ud we propose an intelligent HO prediction scheme with advance resource preparation in order to minimise\ud the HO signalling latency. Numerical and simulation results show promising gains in terms of reduction\ud in HO latency and signalling load as compared with conventional approaches.

With its higher bandwidth and lower latency, the LTE/LTE-A network has been successively deployed worldwide, leading to many changes in peoples' lifestyles over the years. Recently, as new demands on the cellular network have appeared from emerging technologies such as the Internet of Things, latency reduction has become a key challenge to supporting emerging technologies and satisfying user expectations. Although latency reduction in the cellular network is a traditional issue that has been studied in various respects, the latency of the LTE/LTE-A radio access network has been undervalued and investigated by very few studies. This article presents the latency issues in the LTE/LTE-A radio access network based on the radio resource control (RRC). Furthermore, we propose new approaches to mitigate involuntary delay by optimizing the procedures of the RRC state transition.

Cognitive radios (CRs) use learning algorithms (LAs) located in the cognition engine (CE) to adapt their behaviour. CRs use LAs for spectrum prediction to enhance their quality of service (QoS). The CR's CE consumes battery power while classifying LAs. The LA classification reduces CR data transmission power and limits CR throughput. This paper proposes a framework to enhance CR QoS in LTE-Advanced (LTE-A). The proposed framework reduces battery power expended in LA classification and increases CR data transmission power. It introduces the radio resource control (RRC); RRC_COGNITIVE state in which the CR pauses LA classification. The framework's performance is evaluated using the CR transmit power and throughput. Simulations show that the proposed framework reduces LA classification power by 65 % on average. The reduction of LA classification power enhances CR transmit power. The CR throughput is enhanced by 23% and 80% when CRs are and are not secondary users (SUs) respectively.

Long Term Evolution (LTE) networks are expected to provide enhanced quality of service (QoS) guaranteed services and a high capacity. In this paper, we propose a novel QoS guaranteed cross-layer scheduling algorithm for LTE system. In fact the LTE scheduler is responsible for efficiently allocating the radio resources among mobile users who have different QoS demands. We focus on the resource blocks allocation and the Medium Access Control (MAC) scheduling algorithm. Our study highlights the impact of the Radio Resource Control (RRC) configuration on the overall performance and the Transport Block (TB) filling during the allocation process. Performance results show that the proposed algorithm is effective in enhancing service fairness, throughput and resource optimization. Our proposal aims to find an agreement between fairness, resource availability, the requested rate and service QoS requirements.

Device-to-Device (D2D) communication is one of the most popular topic in the upcoming device communication. D2D provides access to services through direct or indirect connection path with neighboring devices with or/and without ENodeB (eNB) assistance. Some of the problems faced in this case are discovering process of neighbor user equipment (UE) and services, as well as designing suitable and secure protocols for D2D communication. In this paper, we propose a sidelink based D2D communication, wherein a separate unlicensed band apart from uplink and downlink is considered to be allocated for sidelink and is functional without the presence of eNB. In this paper we present a detailed study of operational procedures at Radio Resource Control (RRC) and Media Access Control (MAC) layers for sidelink based D2D communication along with this various messages handled for D2D communication for both scenarios using sidelink has been discussed. Two scenarios of D2D communications have been considered-for both UE's in-coverage and both UE's' out-of-coverage. The client side architecture of D2D communication with respect to RRC and MAC layers is also presented.

The Radio Resource Control (RRC) state machine has been widely studied to improve application performance and reduce the energy consumption of smart phones. We observe that even a smart phone remains in the RRC state, there may still exist some significant performance change if it simultaneously carry on voice and data services. For example, the Round Trip Time (RTT) will get larger when a voice call comes upon, and may get even larger after finishing the voice call. We conduct in-depth study and find out the primary cause of those phenomena - smart phones may get different physical channels even in the same RRC state. In this paper, we define new states according to which physical channel is allocated to smart phones, then discover a fine-grained state machine which is hidden in the physical layer of user plane, which can explain those phenomena very well. We construct the hidden fine-grained state machine for two carriers, one only supports 3G network in most area and the other supports 4G network. The state machine can help us analyze the interference of voice to data. Using the fine-grained state machine, we also offer some suggestions on how to avoid those performance loss both from the perspective of carriers and users.

This paper proposes a power efficient video streaming mechanism on mobile devices over cellular networks. We first develop an analytical model to identify and quantify the power inefficiency in mobile video streaming, due to the mismatch between HTTP request schedule and the radio resource control schedule. Based on the analytical model, we develop a low power video streaming mechanism by employing the server push technology available in the HTTP/2 protocol. We implemented the server push-based low power streaming mechanism in an HTTP DASH video streaming prototype involving mobile devices and the 4G/LTE cellular network. Our experiments show significant battery power savings on mobile devices using our server push strategy.

Signaling storms in mobile networks, which congest the control plane, are becoming more frequent and severe because misbehaving applications can nowadays spread more rapidly due to the popularity of application marketplaces for smartphones. While previous work on signaling storms consider the processing overhead in the network and energy consumption of the misbehaving User Equipment (UE) only, this paper aims to investigate how signaling storms affect both the energy consumption and bandwidth allocation of normal and misbehaving LTE UEs by constructing a mathematical model which captures the interaction between the UE traffic and the Radio Resource Control state machine and bandwidth allocation mechanism at the eNodeB. Our results show that even if only a small proportion of the UE population is misbehaving, the energy consumption of the radio subsystem of the normal UEs can increase significantly while the time spent actively communicating increases drastically for a normal data session. Moreover, we show that misbehaving UEs have to spend an increasing amount of energy to attack the network when the severity of the signaling storms increases since they also suffer from the attacks.

The RRC(Radio Resource Control) protocol belongs to the 3GPP protocol stack and handles the control plane signalling of Layer 3 between the UE(User Equipment) and the eNB(Evolved Node B). The RRC Connection Re-establishment is one of the RRC main functions and re-establishes which involves the resumption of SRB1 (Signalling Radio Bearer) operation, the re-activation of security and the configuration. In this paper, we proposes the RRC Connection Re-establishment procedure on the UE side when the RLF(radio link failure) is detected or handover failure occurs, etc.

In the LTE systems, battery lifetime and network traffic overhead on control plane may be largely affected by the Discontinuous reception (DRX) configuration and the Radio Resource Control (RRC) Inactivity Timer. In this scenario, the paper proposes an analysis aimed at defining how to properly set the RRC Inactivity Timer to achieve a trade-off between energy savings and traffic overhead on the control plane. The analysis is based on an energy consumption model, whose key parameters are inferred directly from passive measurements carried out by monitoring a commercial eNodeB of one of the Italian Mobile Operators. The results suggest that taking into account the network traffic characteristics is possible to find the RRC inactivity timer value that permits to save energy of user's device while the increase of the signalling load is limited.

The explosive growth of smart mobile user equipments (UEs) boosts the emerging of numerous mobile applications. Most of these applications require an always-online connectivity, which incurs overly-frequent Radio Resource Control (RRC) state transitions, leading to signaling storm and user access failure. To address this issue, many researches focus on avoiding frequent transitions between RRC states by maintaining UEs in the RRC connected state for longer time. However, these researches bring up substantial energy consumption. In this paper, we propose an energy-efficient system signaling control method, by which each UE adjusts its RRC release timer adaptively according to the traffic patterns of mobile applications. Numerical results show that in comparison to the conventional signaling control method, the proposed method can save 27.5% average energy consumption with well-controlled signaling load. Meanwhile, the disparity of user experience is significantly lower.

The 3GPP Long Term Evolution (LTE) wireless technology provides high data rates and improved latency to the end users. Such improvement is obtained from the advanced MAC and PHY layer techniques, which exhaust the battery life of the User Equipment (UE) quickly. To save the power of UE, 3GPP LTE proposes a mechanism called Discontinuous Reception Mechanism (DRX) which lets the UE switch its RF module off when data needs not be transmitted. In this paper, we have developed an analytical model to derive the DRX power saving obtained by the UE in LTE system. Different from other work, the RRC (Radio Resource Control) states transition is considered. The time period for power saving operation is divided into several independent parts to derive the power consumption and the transmission delay. In addition, we introduce the real power consumption model into the derived power saving model to obtain the truly power consumption. The analytical results show the UE with lower packet arrival rate can effectively save more power when entering RRC_IDLE state, and there is a trade-off between the power consumption and the transmission delay.

This paper demonstrates that end-to-end active measurements can give invaluable insights into the nature and characteristics of packet loss in cellular networks. We conduct a large-scale measurement study of packet loss in four UMTS networks. The study is based on active measurements from hundreds of measurement nodes over a period of one year. We find that a significant fraction of loss occurs during pathological and normal Radio Resource Control (RRC) state transitions. The remaining loss exhibits pronounced diurnal patterns and shows a relatively strong correlation between geographically diverse measurement nodes. Our results indicate that the causes of a significant part of the remaining loss lie beyond the radio access network.

Push notification services send messages from servers in the cloud to applications on smartphones at any time to notify the applications or users of new or updated information. These services are characterized by frequent background traffic without user operations that affects the energy consumption of the mobile terminal and cellular network load. These factors are related to the RRC (radio resource control) state. If a server takes the RRC state of the mobile terminals into account and controls the timings for sending messages, the energy consumption and cellular network load can be reduced. In this paper, we propose methods for estimating the RRC state in push servers for controlling messaging timings. The evaluation result shows our method achieved an estimation accuracy of 70 % to 99 % depending on the server load for the estimation.

With the rapid development of internet of things (IoT) with various low-cost machine type communications (MTC) devices, intelligent wearable devices, vehicular sensors and environmental sensors etc, it's anticipated that trillions of wireless nodes in IoT with diversified applications and services may come to life in the fifth generation wireless communication system (5G). These devices, however, may not be handled efficiently by the current wireless communication networks, which were not designed for frequent small data packets and simultaneous massive accesses. In this paper, a novel aggregator based MTC communication architecture is proposed, where the aggregators function as MTC gateways towards the cellular network, combining connections of masive devices into single connection. Correspondingly, based on the aggregated packet characteristics and data relay modes, the aggregators will request for aggregator specific radio resource control (RRC) mechanism. Simply put, always available connectivity is desired for contiguous packets with low latency, while coordinated transmission among multiple aggregators are preferred for packets with larger delay tolerance. Through various analysis and numerical results, MTC communication with aggregators are expected to bring much improved signaling efficiency, thus handling the gigantic pressure on 5G network design from the potential trillions of MTC devices.

In this paper HSPA Release 6 femto and IEEE 802.11g WiFi indoor data solutions are investigated from an end user perspective. Femto and WiFi access points are deployed at typical locations in an urban environment and end user performance is measured. Three key performance indicators (KPI) were defined - downlink and uplink user data rates, latency and mobile power consumption. These three KPIs are of high importance when choosing an indoor data solution. Our measurements show that the downlink and uplink data rates of the WiFi solution are significantly higher than femto data ra tes. Similarly, latency results show that WiFi outperforms the femto solution. Especially, the radio resource control (RRC) connection set-up time increases the latency for the femto. In terms of idle power consumption the best results are obtained when the mobile camps on the femto. Whereas, WiFi performs best in all active mode power consumption measurements. Based on our KPIs, the preferred indoor data solution today is WiFi. The deciding factor is the combined latency and power performance of the WiFi, where WiFi outperforms the femto.

The increasing needs of mobile internet application services running on smartphone is driving the evolution of wireless communication networks, due to the diversity of traffic characteristics in addition to the rapid growth of data volumes. Differently from typical internet services like web browsing and FTP, the pervasive usage of always-on applications can lead to frequent User Equipment (UE) transitions between Radio Resource Control (RRC) states, and result in excessive signaling traffic that need to be accounted in network capacity planning. In this paper, we propose a novel traffic generation framework to obtain the traffic flows generated by a smartphone which is running heterogeneous applications including both typical applications which are selected on the basis of a proposed application level traffic growth forecast, and keep-alive messages from always-on applications. Using such a framework, the radio resource consumed by different types of application can be evaluated. We exemplify the use of the proposed traffic modeling with a case study of a year-by-year radio resource consumption of voice traffic and keep-alive messages in a realistic LTE (Long Term Evolution) network scenario.

Cell edge performance has always been challenging from network planning and performance perspectives. Several cell edge performance techniques and methods have been widely proposed to enhance it. Small cell heterogeneous network deployments (LTE/LTE-A cells and Hotspot 2.0 Passpoint certified access points) enable pervasive mobile experience, seamlessly connecting users though both radio access technologies (RAT). Underlying, 3GPP's Access Network Discovery and Selection Function (ANDSF) provides transparent policy-based RAT selection and traffic steering. Current ANDSF specifications, however, do not support Real Time (RT) network performance awareness, crucial to intelligently steer traffic or users between 3GPP and non-3GPP RATs. Our contribution is a method of enhancing global LTE-LTE/A performance, focusing on cell edges by a) enhancing ANDSF capabilities using Radio Resource Control (RRC) System Information Block (SIB) to convey RT data to steering decision and b) intelligently steer low performance cell edge users to non-3GPP RAT access points, which we consider to be HS2.0.

The fast adoption of smart phone triggers the migration of tremendous internet applications from desktop to mobile terminal, as well as various inherently mobile oriented applications. Among them, Instant Message (IM) represents a large portion of applications. Unlike over traditional wired network, IM brought a great trouble to the mobile network called “signaling storm” due to its small data dominated traffic profile. This paper conducts a comprehensive analysis on the signaling/control overhead of IM, compared with streaming oriented voice/video applications. It figures out that shift from connection oriented to connectionless can solve the problem. A new slim Radio Resource Control (RRC) state with corresponding slim signaling transfer procedures is proposed for the connectionless scheme. Numerical results show that great signaling/control saving can be achieved with our new design.

Even though Evolved Packet System (EPS) features flat-IP architecture, it is essentially a connection oriented system and establishes logical bearers between the User Equipment (UE) and the core network entities for any user data transmission. EPS was designed assuming high speed real-time bulk multimedia data transfer; so initial cost of bearer setup signaling for user plane data is justified. However, this basic assumption is changed due to very small and infrequent background data transfer by the smartphone's always-on applications most of the time when smartphone is not in active use. To transmit this background data, UE incurs frequent idle to connected state transitions and require costly disproportionate signaling overhead for EPS bearer and Radio Resource Control (RRC) connection setup/release procedure. This paper presents a connectionless transmission (CLT) scheme for efficient exchange of background data without establishing the EPS bearer and RRC connection. In the proposed CLT scheme, the data packets are made self-sustainable by carrying routing information in the packet's header. These self-sustained packets are carried through modified Random Access Channel (RACH) procedure between the UE and the eNodeB. Further, another novel aspect of the CLT scheme is to establish common user plane bearers between the radio access network and packet gateways in the core network, to forward self-sustain data packets using the routing information. Our simulation results show CLT scheme reduces the signaling overhead significantly compared to the traditional connection oriented transmission.

Interspersing small cell eNodeBs (SCeNBs) among macrocell eNodeBs (MeNBs) is a key solution for boosting the spectral efficiency of beyond LTE-Advanced (LTE-B) networks, enabled mainly by the shorter distance between user equipments (UEs) and SCeNBs. However, the smaller coverage area of SCeNBs leads to frequent UE handovers in high mobility scenarios, which implies increased signaling overhead and chances of radio link failure (RLF). If control channels or higher-layer Radio Resource Control (RRC) signals are transmitted from MeNBs, then the necessity of frequent UE handovers can be reduced significantly due to the much larger MeNB coverage region. This is the motivation behind the Control-plane/User-plane (C/U) split architecture and dual connectivity solutions. In this paper we examine several issues regarding the pairing of base stations that separately transmit control and data channels, and the grouping of mobile UEs with such MeNB-SCeNB pairs. A novel method based on stable matching theory is proposed that takes into account the non-ideal backhaul links between base stations, their existing traffic loads, and signal strengths from eNBs to various UEs. Simulation results demonstrate that the proposed method is an effective solution for enhancing mobility robustness in HetNets with non-ideal backhaul links.

3GPP has started to investigate feasibility of a low cost machine type communication (LC-MTC) terminal class in LTE networks in Release 12 aiming to be competitive with that of GSM/GPRS terminals targeting the same low-end MTC market with improved coverage. LC-MTC devices are expected to have limited power source. Since LTE technology is relatively more power hungry compared to GSM/GPRS, device power efficiency is one of the crucial requirements for LC-MTC over LTE networks. In this paper, we focus on exploring mechanisms to reduce power consumption for LC-MTC in LTE networks. Most of the current LTE power saving mechanisms are designed and optimized for human-to-human (H2H) communications which are not attractive for LC-MTC as traffic characteristics and service requirements for LC-MTC are expected to be largely different than those of H2H Communications. LC-MTC usually has very infrequent and small traffic burst mostly in UL. Therefore, one possible solution to maximize the power saving is to maximize the time with LTE radio turned off in between the traffic bursts. In this paper, we analyze the impact of turning off LTE radio without moving LC-MTC into Radio Resource Control (RRC) Idle and reducing the RRC Connected tail time (i.e., RRC Inactivity Timer). Our results show that turning LTE radio off after data transmission can achieve upto 95.28% reduction in power consumption compared to that in case of moving device to RRC Idle. Reducing RRC Connected tail time further improves the device power saving.

In this study, the speed test software Nemo Handy installed on an engineering-mode mobile phone was used to measure the key performance indicators (KPI) of circuit-switched (CS) and packet-switched (PS) signal parameters generated from Node B located around the venue of the Spring Scream festival held in Kenting, Taiwan between April 3, 2013 and April 7, 2013. The measured signal parameters were then processed using the postprocessing software of Nemo Outdoor and Nemo Analyze to examine the quality of the communication signals. The items of the KPI parameters that were analyzed included slope, standard deviation (SD), drop call, UL throughput, DL throughput, and web open time (web time). The resulting data were then compared with the internal data generated at the system end of the switching device to understand the behavior of mobile phone users in various environments. Based on the varying behavioral models, the parameters of the node B were adjusted to optimize the performance of the node B. During the mobility test, 1 drop call occurred out of the 55 call attempts, yielding a DCR of 1.818%. According to the Splunk software at the system end, the DCRs during circuit switching and packet switching remained below 2%. The connect success rate of the radio resource control (RRC) and radio access bearer (RAB) was maintained above 98% and 97%, respectively. This high success rate was sustained despite using the mobile phone during peak hours, indicating that the resources available at the system end are sufficient.

Two Radio Resource Control states have been proposed in LTE and implemented to ensure low UE power consumption and high network resource availability. Transiting between these two states optimizes network performance if tuned properly. Currently, a UE switches from the LTE_ACTIVE state to the LTE_IDLE state after a pre-configured static inactivity duration. This paper seeks to demonstrate that no static timeout is optimal for all users at all times. In addition, a user-level dynamic decision algorithm is proposed to have fine-grain user level optimization. Since achieving better efficiency is related to context awareness, we present a solution that allows the UE to auto-learn its traffic behavior. The dynamic algorithm was applied to five different user load scenarios of combined application and legacy traffic, and the results showed that we are able to attain power savings of up to 30% when compared to the fixed timeout case.

In 3rd Generation Partnership Project (3GPP), enhancements of Diverse Data Applications (eDDA) work item has targeted at improving always-on connectivity for smartphones, identifying and specifying mechanisms at the Radio Access Network (RAN) level to enhance the ability of 3GPP Long Term Evolution (LTE) to handle diverse traffic profiles. The key aspects are the Radio Resource Control (RRC) release timer for User Equipment (UE) state control between connected and idle modes, and Discontinuous Reception (DRX) targeted for minimizing the UE power consumption in connected state. There exist important tradeoffs between UE power consumption, Quality-of-Service and RAN/core network signalling load. What's more, these tradeoffs may be dependent on the UE mobility/velocity. In this article we study the effect of DRX and RRC release timer parameterization on UE mobility performance in heterogeneous networks. These results can be applied to parameter optimization of DRX and RRC release.

This paper investigates the potentials of Traffic Steering (TS) in Carrier Aggregation (CA) deployments. TS is defined as the mechanism to optimally distribute traffic among the deployed cells. Obviously, such functionality is rather crucial in scenarios where solely non-CA User Equipments (UE) are present. The introduction of CA is expected to simplify inter-layer load balancing, as CA UEs can concurrently connect to multiple carriers. In order to evaluate the relevance of TS in CA environments, a simple TS framework is developed, where load balancing decisions are applied in both Radio Resource Control (RRC) UE states. System level simulations have been conducted for different deployments and CA UE ratios. The corresponding results have shown that TS should be mandatory for any CA penetration below 50%, irrespective to the network deployment. Nevertheless, for scenarios where the number of deployed carriers is greater than the multi-carrier connectivity capabilities of the CA device, TS should be applied even for higher CA UE ratios, since the CA scheduler cannot solely resolve the load imbalances.

In order to effectively deliver traffic from different applications, providing end-to-end Quality of Service (QoS) is critical in Long Term Evolution (LTE) networks. Mobility requires special handling of QoS enforcement rules and methods. The LTE QoS Signaling (LQSIG) protocol presented in this paper will allow ensuring resource reservation before using a data path. Operation of the proposed protocol in different mobility scenarios is also explained. The key features of the protocol includes LTE QoS model mapping to QSPEC (QoS Specification) objects used in reservation and interworking with mobility protocols in the LTE protocol stack, especially with Radio Resource Control (RRC). The basics of an analytical model is proposed in order to determine the blocking probability at the bottlenecks of LTE network.

The high signaling load in today's UMTS networks has recently lead to severe problems and network outages of several hours, so called Signaling Storms. The reason is that certain network access patterns of popular smart-phone applications trigger frequent connection re-establishments, which are signaled to the network via the radio resource control (RRC) protocol. As a consequence of the network agnostic implementation of smart-phone applications, entities of the mobile network operator may experience overload, while energy consumption at the smart-phones is mutually determined. The aim of this work is to study the impact of traffic characteristics on the power consumption of the smart-phone and the signaling messages in the mobile network. For that purpose, we first develop a simple model for the RRC states of a smart-phone. Second, we estimate the resulting power drain and the signalling traffic of the smart-phone. Then, we investigate the applicability of our model by comparing analytical with simulation results for real-world smart-phone traffic measurements. Finally, we evaluate the effect of network parameter optimization on traffic with different statistical characteristics. Our counter-intuitive results show that in particular bursty traffic patterns are suitable for UMTS networks while periodic patterns may cause increased power consumption and signaling overload - in contrast to classical queueing systems.

Component carriers (CCs) in a Long Term Evolution - Advanced (LTE-A) system are limited by maximum 100 radio bearers (RBs) on a 20 MHz CC due to a fixed 15 KHz subcarrier bandwidth. However it is able to be changed in the future, so that a study regarding heterogeneous CCs which have diverse RBs above 100 on a CC is needed at this moment. To support non-contiguous carrier aggregation (CA) with the these conditions, a heterogeneous joint CC packet scheduling algorithm interacting with a radio resource control (RRC) is considered in this paper. The performance of the joint CC packet scheduling algorithm on heterogeneous CCs with different channel characteristics has been analyzed and compared through computer simulations as well. According to the results, we found that an 800 MHz CC exhibits approximately 4 dB better channel gains than a 2.1 GHz CC. We also obtained a capacity increase of about 15-40% for a joint CC maximum rate (MR) algorithm and about 2-28 % for a joint CC proportional fair (PF) algorithm when the number of users is increased. On the other hand, in a round-robin (RR) scenario, we were unable to notice any differences between the independent CC and joint CC packet scheduling policies. Furthermore, looking at the impacts of different amounts of RBs on 800 MHz + 2.1 GHz CCs, we can conclude that a one-to-one RB ratio with respect to the MR, PF, and RR algorithms has a better performance compared to other cases, and thus, owing to the better channel gain, the smaller the RBs of the 800 MHz CC, the better the performance achieved.

In order to effectively deliver traffic from different applications, providing end-to-end Quality of Service (QoS) is critical in Long Term Evolution (LTE) networks. Mobility requires special handling of QoS enforcement rules and methods. The LTE QoS Signaling (LQSIG) protocol presented in this paper will allow ensuring resource reservation before using a data path. Operation of the proposed protocol in different mobility scenarios is also explained. The key features of the protocol includes LTE QoS model mapping to QSPEC objects used in reservation and interworking with mobility protocols in the LTE protocol stack, especially with Radio Resource Control (RRC). The basics of an analytical model is proposed in order to determine the blocking probability at the bottlenecks of LTE network.

Keep-alive messages generated from always-on type applications on smartphones can lead to frequent transitions between Long Term Evolution (LTE) Radio Resource Control (RRC) states, pushing significant increase of signaling traffic. In this paper, we investigate the performance of signaling overhead caused by keep-alive messages based on LTE RRC state transition procedure for various RRC inactivity timer settings. We propose a series of metrics for evaluating the signaling load in terms of system resource consumption on data and control channels for both uplink and downlink. The results show that although the RRC signaling overhead make keep-alive messages transmission with low efficiency, it will not consume the system resource dramatically and overload LTE network. The results also show that proper inactivity timer setting will reduce the signaling overhead and improve the efficiency of keep-alive messages transmission.

With the rise of the user base of smartphones, the cellular networks are facing increasing uplink signalling traffic pressure caused mainly by the soaring background traffic of smartphone applications. Therefore, this paper studies the LTE radio resource control (RRC) state transition, which is highly related to the amount of signalling traffic, caused by the background traffic. Firstly, we propose a general method for generating the background traffic using a burst model, taking the Gtalk as an example. Secondly, a novel theoretical model is proposed to calculate the number of RRC state transition, the probability of a smartphone's being in RRC CONNECTED and the distribution of the number of smartphones in RRC CONNECTED at a given epoch, all of which are key metrics for the cellular networks. Finally, both theoretical and simulation results are compared for a typical LTE macro cell scenario containing 300 cell phones, 80% of which are smartphones. The study also shows that the Gaussian distribution, which turns out to be a very good approximation, can be used to fit the distribution of the instantaneous number of smartphones in RRC CONNECTED in a LTE cell.

This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle users can be steered towards higher priority carriers whenever coverage allows it. However, such an approach may overload the prioritized layers. For that purpose, an enhanced scheme is proposed, where priorities are adjusted on a user basis and are provided to the terminal via the connection release signaling. The priority adjustment is based on both the Composite Available Capacity (CAC) and the radio conditions of the candidate layers. Compared to broadcast AP, the proposed scheme achieves better load balancing performance and improves network capacity, given that the User Equipment (UE) inactivity periods are not significantly long. Finally, better alignment between the RRC Connected and Idle mobility procedures is observed, guarantying significant decrease of handovers/reselections and potential battery life savings by minimizing the Inter-Frequency (IF) measurement rate in the RRC Idle.