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A 5G network can provide more comprehensive bandwidth connectivity for the industry 4.0 environment, which requires faster and tremendous data transmission. This study demonstrates the 5G network performance evaluation with MEC, without MEC, WiFi 6, and Ethernet networks. Usually, a 5G network engages with Multi-access Edge Computing, providing the computing functions dedicated to the users on edge nodes. The MEC network architecture presents significant facilities, a network schematic, and data transmission routers. The field test performs high-definition streaming video and heavy-traffic load testing to evaluate the performance based on different protocols by comparing throughput, latency, jitter, and packet loss rate. MEC network performance, streaming video performance, and load test evaluation results reveal that the 5G network working with MEC achieved better performance than when it was working without MEC. The MEC can improve data transmission efficiency by dedicated configuration but is only accessible with authentication from mobile network operators (MNOs). Therefore, MNOs should offer industrial private network users partial authentication for accessing MEC functionality to improve network feasibility and efficiency. In conclusion, this work illustrates the 5G network implementation and performance measurement for constructing a smart factory.

International audience; 5G networks generate massive (quasi-) real-time data streams that different network apps can exploit to implement sophisticated single-or cross-domain control and management logic. This paper presents ElasticSDK, a Software Development Kit specially designed to abstract the development and chaining of such agile 5G monitoring apps for the control, management, and coordination of the underlying 5G network heterogeneous modules. Custom apps can collect, incrementally process and further expose flows in a flexible Pub/Sub fashion via appropriate SDK API calls, thus sharing both raw and complex data flows among themselves. Furthermore, the design of ElasticSDK allows respecting typical 5G data ownership and privacy models, as desired by the different 5G stakeholders ranging from physical infrastructure providers up to service providers over slicing. Finally, we provide two important contributions to the 5G open-source research community: (i) a RAN monitoring prototype implementation over the ElasticSearch and FlexRAN platforms that allows to demonstrate ElasticSDK app development and capturing hierarchical control features of typical SDN-enabled 5G architectures, and (ii) a first-ever publicly available dataset of realistic 5G RAN monitoring traces.

This paper summarizes the development of open- source protocol stacks in OpenAirInterface (OAI) Narrowband Internet-of-Things (NB-IoT) enhanced Node B (eNB) project based on 3GPP Release 13 (R’13) standard. We focus on the design of medium access control (MAC) layer for NB-IoT eNB since the other layers are developed based on existing stacks of OAI Long-Term Evolution (LTE) eNB. The main function blocks of the medium access control (MAC) layer and the flowcharts of the major functions are elaborated. This work can be a starting point for the researchers to contribute to the open-source community to support 5G massive machine-type communication services.

Improving energy efficiency is crucial since it helps to bring benefit to the environment as well as cost savings. An accurate electricity load prediction offers opportunities to building manager for having a better planning of their building operational strategies, and increase its efficiency. Electricity load prediction itself has become a challenging task due to its complex and non-stationary pattern. This study proposes a hybrid algorithm that combines fuzzy c-means clustering approach, empirical mode decomposition, and support vector regression to predict building electricity load in the university. Experimental results demonstrated that the proposed hybrid method could improve SVR prediction accuracy.

Random access channel (RACH) is the first step that needs to be conducted by any devices which require data transmission in modern cellular networks. Since LTE and beyond also often used to serve IoT application due to its wide coverage and availability, conserving energy is important. This paper presents a flexible preamble allocation scheme which is applied in RACH procedure and evaluates its energy consumption. The flexible preamble allocation enables base station to fine-tune its preamble allocation, which mainly used to prioritize H2H services over IoT ones. Such access prioritization translates in more efficient signaling transmissions during RACH procedure by reducing collision. The result demonstrates that the scheme can effectively reduce energy usage compared with the standard RACH procedure with shared preamble pool.

This paper presents the design and implementation of an IoT-enabled water dispenser system. We use the communication module of the commercial water dispenser and our own gateway to collect the temperatures of the hot, warm, and cold water tanks, users’ usage of the three water tanks. We use a commercial clamp meter to estimate the power consumption of the water dispenser. Based on the collected data, we can learn the operation of the water dispenser and the users’ behavior. We further demonstrate our preliminary results to use the proposed system to adjust configurable parameters to optimize the power consumption of the water dispenser.

LoRaWAN is a promising solution of Low-power wide area network (LPWAN) operating in unlicensed spectrum to support long range wireless services for Internet of Things (IoTs). However, with the growth of IoT devices deployed in a fixed geographic area, the immunity to interference on the communication increases significantly. Attackers may utilize such situation to jam packet transmission by emitting RF interference signal at the same time when a LoRa end node is sending data to the LoRa gateway. As a consequence, the transmission of the LoRa end node would fail due to collision which would in turn reduce the network performance. In this paper, we implement a LoRa jammer on commercial LoRa devices by modifying the open source and figure out the proper setting of the jammer through three scenarios aiming to evaluate the influence of LoRa transmission configuration on jamming performance. Specifically, the impact of non-orthogonality of LoRa transmission on jamming effect is investigated. Possible countermeasures for LoRaWAN are then presented to alleviate the jamming attacks.

In this paper, we investigate how OAI can be used on top of M-CORD, and present the deployment results demonstrating a virtualized 5G Radio Access Network (RAN)-Core infrastructure on top of M-CORD. Currently, both Mosaic5G and mobile central office re-architectured as a datacenter (MCORD) utilizes OAI and the cloud RAN idea to virtualize some RAN functions and core network functions. Both Mosaic-5G and M-CORD enables virtualization and softwarization of 5G RAN-CORE infrastructure following SDN and NFV principles. In M-CORD, such a feature is extended to transport network to manage traffic in fronthaul and backhaul network segment. Specifically, both Software defined network (SDN) and (NFV) are applied not only to dynamically slice the network resources but also to manage traffic engineering in both RAN and core network aiming to support the requirements of network services. The deployment results demonstrate the procedure integrating virtualized OAI RAN and core network into M-CORD.

Narrowband internet-of things (NB-IoT) is a 3GPP standard designed for Internet-of-Things (IoT) application. This paper presents the design consideration and possible options of a UE-specific uplink (UL) scheduler for NB-IoT system. We developed a unitary C emulation platform to verify the effectiveness of the proposed approaches, which is currently under integration within the OpenAirInterface NB-IoT project.

Narrowband Internet-of-things (NB-IoT) is a new standard developed by 3rd generation partnership project (3GPP) to provide IoT services in licensed spectrum. It adopts existing LTE-Advanced (LTE-A) orthogonal frequency-division multiple access (OFDMA) technology but each carrier only requires 180 kHz bandwidth. It allows an operator to replace a GSM carrier (200 kHz) in ‘stand-alone’ mode; to utilize a physical resource block of 180 kHz within a normal LTE carrier in ‘in-band’ mode; or to occupy an unused resource block within the guard-band of a LTE carrier in ‘guard band’ mode [1]. In April 2017, the OpenAirInterface™ Software Alliance (OSA) launches a new project to develop a software-defined-radio-based NB-IoT Evolved Node B (eNB). This poster summarizes the original research work conducted for the implementation of an open source eNB. This work can be used by researchers and users to validate important research ideas and demonstrate realistic applications [2].

Narrowband Internet of Things (NB-IoT) is a new access technology introduced by 3GPP. It aims to support massive machine-type communications services in wide area. This work presents an analytical model to estimate access success probability and average access delay of random access (RA) procedure for three coverage enhancement (CE) levels in NB-IoT. The behavior of RA procedure in NB-IoT is analyzed and accuracy of the analysis is verified by computer simulations.

This paper analyzes the performance of RACH-based small data transmission scheme for LTE/LTE-A networks. Power consumption at random access, signaling, and data transmission phases are analyzed. The energy efficiency of the scheme under different number of preambles, offered loads, packet size and packet inter-arrival time is investigated. The results show that RACH-based small data transmission scheme consumes less energy when more preambles are used and less contending devices are involved. More importantly, the energy consumption of this scheme can be further decreased by increasing the bearer timer.

Long-term evolution (LTE)-based vehicular-to-everything (V2X) service is one of the promising technologies for supporting intelligent transportation systems (ITSs). LTE adopts a request-grant approach for allocating wireless resources. Each user follows a contention-based random access (RA) procedure to transmit its request. However, this procedure may result in unbounded delay if too many users compete for limited RA resources. Therefore, prioritized critical access in the LTE RA procedure is required to differentiate critical V2X services from noncritical ones.

This paper presents an iterative contending-user estimation method to analyze the normalized throughput, the packet-dropping probability, the average access delay, and the variance of the access delay for finite-population slotted ALOHA system supporting multiple access-class traffic. We demonstrate the way to extend the model to accurately predict the access delay of small data transmissions in OFDMA system which is used in LTE or WiMAX systems adopting immediate-first-transmission and delayed-first-transmission protocol.

For LTE-A TDD systems supporting DL heavy asymmetry traffic, the number of downlink (DL) subframes are much higher than that of uplink (UL) subframes. The HARQ feedbacks of multiple DL tranport blocks may be transmitted in one UL subframe. Time-bundling is a technique proposed to reduce the HARQ signaling overhead by combining multiple ACK/NACKs into one using ‘AND’ operation. In this paper, we propose a window-based HARQ time-bundling scheme to further enhance the legacy scheme. An analytical model is provided to analyze the performance of proposed scheme. We will show that the proposed scheme can reduce the signaling overhead and the analytical model can accurately estimate the performance of the proposed scheme.

A group of multi-mode wearable devices or mobile terminals (MTs) may be carried by the same vehicle and then perform group handover during the movement within heterogeneous networks. However, it is a challenging work to determine a proper target network which is good for both MTs and the network provider. This paper presents a simulated-annealing-based group handover decision scheme to reduce the group handover blocking ratio, decrease the number of handover, balance the traffic load between networks, and ensure the target quality of service (QoS) requirements of MTs. Simulation results show that the proposed scheme can reduce the group handover blocking ratio efficiently and balance the load. Besides, when the number of group MTs is not quite large, the number of handover can be reduced and the QoS requirements can be fulfilled.

Due to the random access (RA) process, machine-type communication (MTC) devices of a group may delay until the time point of the next polling of another groups and lead to a serious access delay problem. To solve this problem, in this paper, we investigate a dynamic backoff indicator (BI) assignment (DBA) algorithm that lets the delayed MTC devices speed up to finish their RA within an expected period of time. The proposed method also realizes the crucial concept of cyber-physical systems (CPS). Simulation results and analyses validate the effects of CPS on reducing collision probability in large-scale MTC.

The ability to provide handset tracking or positioning system independent from the available commercial mobile network is required in emergency. In some cases, it is possible that the commercial mobile networks are suspended due to the natural disaster, terrorist attack or other emergency condition. The commercial mobile networks might also unavailable in the remote areas where some extreme sports or research exploration take place. During emergency evacuation, detecting handset location might be a big help for the rescue team to loacte the victim. This work analyzes the system architecture of OpenBTS and AirProbe GSM-Receiver, and proposed a way to achieve affordable mobile phone positioning with these open source platform. The target is to build a cost-effective prototype which able to detect handset position more precisely. An effective approach to increase the positioning accuracy is also presented. The result from this paper can be used as a reference of how to develop a cost effective mobile positioning system.

Relay technology is one of the techniques proposed to enhance the capacity of Long Term Evolution-Advanced (LTE-A) networks. In an LTE-A relay network, each serving relay node has to store packets for its mobile users and forward the remaining packets to another node during handover. However, increasing the number of forwarded packets will result in the degradation of the users throughput. Flow control and pre-buffering schemes are the two main schemes proposed to reduce the number of forwarded packets in LTE-A relay networks. Existing studies assumes the two schemes are independently operated. However, ignoring the effect of buffer overflow at the pre-buffering queue in a flow control scheme may result in ineffective operation. This paper presents a pre-buffering-aware flow control scheme (PFCS) for an LTE-A relay network that jointly considers the effects of both flow control and pre-buffering schemes. The proposed PFCS can significantly improve user's throughput by preventing both buffer overflow and buffer underflow of the local queue at the serving relay node and minimizing the number of forwarded packets. Simulation results show that the PFCS can provide a better throughput than the traditional flow control schemes because the effect of the pre-buffering scheme can minimize the number of forwarded packets.

Current heterogeneous wireless networks often overlap because of their complementary characteristics and the large deployment of various wireless access technologies. Mobile devices, which are equipped with multiple wireless interfaces, called multiple radio access technologies (multi-RATs) mobile stations (MSs), are also becoming increasingly popular. Therefore, common radio resource management (CRRM) has been proposed to coordinate heterogeneous radio resource allocations and improve the resource utilization of heterogeneous wireless networks. However, CRRM is an NP-hard problem, and low-complexity approaches for dynamic resource management are in high demand. In this paper, the resource request and allocation between multi-RAT MSs and heterogeneous wireless networks are modeled as a directed graph. Thus, the problem of searching for feasible radio resource allocations is simplified to finding trees in a directed graph. Based on the proposed model, a heuristic scheme can be used to find a feasible solution efficiently, and dynamically adjust the workload of heterogeneous BSs to accommodate new requests. Experimental results demonstrate that the heuristic scheme can reduce the request reject rate by 10%-55% compared with conventional approaches.

Proprietary protocols on the Internet often pose challenges for users and analysts to determine how secure the applications are or how easy private information can be accessed. This work presents a tool that processes packets generated by Skype and analyzes its proprietary implementation. The goal of the exercise is to determine how one may reverse engineer a proprietary protocol and obtain private information. The results demonstrate that a buddy-list of a target user can be obtained through the developed Skype Protocol Analyzer.

Relaying technology is a cost-effective solution for achieving throughput enhancement for cell-edge users or extending the cell coverage for the 3GPP LTE-A systems. In this study, we investigate the flow control scheme in the LTE-A relay networks employing the Type-I relay nodes (RNs). However, the buffer-overflow problem [7, 8] caused by high-speed arrival traffic and the handover forwarding problem caused by UE's handover are two main issues that affect the performance of 3GPP LTE-A relay networks. To mitigate these problems, we present a dynamic two-threshold flow control scheme (DTFCS) which can dynamically adjust the upper buffer-threshold of RN based on the channel quality. Results showed that DTFCS can reduce 40% of the total number of forwarding packets during the handover when compared with the two-threshold flow control scheme. Additionally, when the proposed scheme is compared to single-threshold flow control scheme, DTFCS excels by imposing much less signaling overhead on the expense of a slight increase in the number of forwarding packets.

Group paging is one of the mechanisms proposed to resolve the radio access network (RAN) overload problem resulted from simultaneous channel access from huge machine devices [1]. This paper presents a consecutive group paging to enhance the performance of group paging. In consecutive group paging, the base station reserves multiple paging cycles to page the same group of users consecutively such that UEs which failed in the earlier paging cycles can perform random-access procedure again in the later paging cycles. We utilize the analytical model presented in [2] to derive the performance metrics of consecutive group paging. The optimal group size, total number of reserved radio resource and the maximum number of preamble transmission are derived for each value of paging cycle threshold. The accuracy of the proposed analytical model is verified via computer simulations. Simulation results demonstrate that the proposed consecutive group paging enhances the performance of group paging.

Random access channels (RACHs) in cellular networks are normally designed for Poisson-distributed arrivals with a constant rate. Unexpected bursty arrivals may result in severely collisions in RACHs and thus, degrade users' service qualities. This paper presents an analytical model to investigate the transient behavior of the RACHs with bursty arrivals generated in a specific time interval in OFDMA wireless networks. The proposed model considers the effect of new arrivals and the real-world implementation constraints of the OFDMA random access procedure such as periodic access characteristic, uniform random backoff policy, and power-ramping effect. The average number of contending and success mobile stations (MSs) in each random-access slot are then derived using the proposed model. The accuracy of the proposed model was verified through computer simulations and the results show the accuracy of the analysis.

Smart meter is one of the novel applications in next generation cellular networks. Group paging can effectively solve the RAN overload control problem in 3GPP LTE, but the usage efficiency of the radio resource is needed to be improved. This paper proposed a dynamic radio resource allocation algorithm to solve the inefficiency problem.

A CDMA-based common channel is a shared uplink channel that multiple users may send their event- specific CDMA codes to indicate their status. In such a channel, the base station may fail to detect a transmitted CDMA code due to the channel fading effect and the multiple access interference (MAI) resulting from the simultaneous transmission of the other CDMA codes. This paper presents system architecture to detect the transmitted CDMA codes in a CDMA-based common channel. A dynamic-threshold- setting method is presented to reduce the detection time and maximize the detection probability. A selective-retransmission method is further proposed to enhance the detection probability by exploring the time-diversity gain. Simulations results showed the proposed method may reduce the number of required radio resource units and achieve a low detection error probability than conventional methods. Hence, it could be a potential solution to reduce huge uplink singling overhead resulted from the simultaneous feedbacks from all multicast/broadcast subscribers.

Both the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE-Advanced) and IEEE 802.16m rely on relay technique to ameliorate cell edge throughput. Despite the throughput benefit achieved by relay technique, LTE-Advanced relay network is vulnerable to frequent handoffs, which can degrade the dropping performance, an important quality-of-service metric concerning realtime communications. This paper proposes a mathematical model to analyze the call dropping performance of the relay station (RS)-first channel access scheme, which prefers a RS-channel over an eNode-B (eNB)-channel when determining an access channel for a new and a handoff call. Closed-form analytical result is derived for the dropping probability of the RS-first policy and based on the result a numerical study is conducted to evaluate the influences of diverse parameters on the dropping performance. The result obtained in this paper can be availed of to develop appropriate call admission strategies in LTE-Advanced relay networks.

Relay is one of the key technologies used by both the Third Generation Partnership Project (3GPP) Long Term Evolution-Advanced (LTE-Advanced) and IEEE 802.16m to ameliorate cell edge throughput. Despite the throughput enhancement achieved by deploying relay stations (RSs), wireless systems supporting relay are vulnerable to frequent handoffs, which deteriorate the dropping performance of realtime communications. This paper proposes a mathematical model to appraise the dropping performance of the eNB-first channel access policy in LTE-Advanced relay networks. The eNB-first policy prefers an eNB-channel over a RS-channel when determining an access channel for a new and a handoff call. Closed-form analytical result is obtained for the dropping probability of the eNB-first policy and based on the result a numerical study is conducted to evaluate the influences of various parameters on the dropping performance. The result developed in this paper can be used to adjust the call admission control strategies to get acceptable dropping performance in LTE-Advanced relay networks.

Multicast and broadcast service (MBS) is one of the important services for next generation wireless systems. Normally, the base station (BS) may perform advance radio resource management functionalities based on the channel quality indicator (CQI) reports sent by MBS subscribers. However, the CQI reports lead to high signaling overhead at the uplink. This paper proposed a common feedback channel to reduce the uplink signaling overhead. A simple dynamic modulation and coding scheme (MCS) is then presented to improve the spectral efficiency based on the limited information carried by the common feedback channel. Simulation results showed that the proposed method could enhance the spectral efficiency with reduced signaling overhead. The results also demonstrated the robustness of the common feedback channel in the presence of feedback errors.

A human centric communication network (HCCN) is a communication network offering human centric (or, social-network-based) mobile Internet services. This paper proposes a three-layer network architecture to model the relationship among users, their social groups, and the serving radio access networks for HCCN. Based on this model, several advertising techniques in HCCN are investigated. Simulation results showed the effectiveness of four algorithms in different application scenarios.

It is not easy to achieve real-time video transmission testbed on WiMax, due to the lack availability of WiMax networks. This paper presents a ns-2 based emulator to evaluate the quality of multicast video services transmitted over an IEEE 802.16 wireless network. The impact of the modulation schemes and the cyclic prefix, on the throughput and video quality were discussed and the performance of the proposed emulator was evaluated. Specially, the results about the emulator's performance are relevant when real-time services are taken into account. The main contribution in this paper is the general guidelines provided to develop an efficient real-time multicast streaming video testbed on wireless networks, exploiting the potentialities of a tool as ns-2. Keywordsns-2; WiMAX; multicast video streaming testbed.

Multicast and broadcast service (MBS) is one of the important services for next generation wireless systems. In WiMAX, the radio resource unit (i.e., time, frequency, code, etc.) for MBS is centralized allocated by a network device named Anchor ASN-GW. The ASN-GW has to ensure that non-overlapping radio resource units are allocated to BSs for delivering different MBS contents. This paper presents a method to allocate radio resource units in overlapping MBS Zones. We proposed radio resource allocation and re-allocation algorithms to minimize the number of re-allocated resource unit due to the change of MBS Zones topology. Simulation result shows that the proposed algorithms can reduce the number of re-allocations and thus, reduce the signaling message exchanged in the air interface and the core network.

It has been shown that IEEE 802.11 DCF medium access control (MAC) protocol may not be suitable for multihop wireless networks due to its relatively low throughput and severely unfairness problems. A tokenpassing MAC protocol, named Ripple, has been proposed to enhance the throughput of DCF by utilizing spatial reuse. However, two perfect assumptions of ‘fixed-length data packet’ and ‘identical interference range and transmission range’ in Ripple make it less practical in the real world. This paper proposes an Enhanced Ripple (E-Ripple) protocol aiming to remove the two restrictions. An analytical model is presented to estimate the performance of E-Ripple and the accuracy of the analysis is then verified via computer simulations. The results indicate that E-Ripple performs well in such a non-perfect environment.

A common problem of a multi-hop wireless backhaul network (WBN) is the end-to-end throughput of a relay node is location-dependent. That is, the closest relay node to the gateway will get the most bandwidth. This paper presents a location-independent scheduling mechanism (LISM) for WBNs. LISM adopts a simple time-stamp-based approach to resolve the location-dependent problem and utilizes a dual-queue approach to minimize the sorting complexity. Simulation results indicate that LISM successfully solves the location-dependent problem.

A multi-hop wireless metropolitan area network (WMAN) is a metropolitan area network that adopts the wireless multi-hop technique to provide high-speed data link between adjacent nodes for metropolitan area. This work presents an improved wireless token ring (IWTRP) protocol for W-MAN. IWTRP adopts the concept of spatial reuse to enhance the throughput of the W-MAN via using multiple tokens. It provides mechanisms to enable multi-token circulation within a ring and to prevent from the possible packet collisions. An analytical model is further proposed to derive the per-node saturation throughput of the W-MAN. Simulation results demonstrate the accuracy of the analysis and the superiority of IWTRP

A common problem of a multi-hop wireless backhaul network (WBN) is the end-to-end throughput of a relay node is location-dependent. That is, the closest relay node to the gateway gets the most bandwidth. The location-dependent problem may be solved by adopting the concept of virtual-timestamp-based scheduling. This paper presents a queueing model to analyze the performance of the proposed concept. The accuracy of the analysis is verified via computer simulation. Simulation results indicate the accuracy of the analysis and the effectiveness of the proposed concept.

This work presents a power-strength-based selective forwarding (PSF) mechanism to efficiently flood route requests (RREQs) during route discovery in multihop cellular networks (MCNs). In PSF, each mobile station utilizes the received power-strength, instead of connectivity or overheard information, to determine itself whether to be a forwarding participant or not. It reduces the signaling overhead and prevent unnecessary interference during the route discovery. An analytical method is proposed to set the power thresholds required to ensure a given connectivity probability. The accuracy of the proposed method has been verified via computer simulation. The results show that the proposed PSF mechanism can significantly reduce the number of RREQs while ensuring the connectivity probability.

Wireless mesh network, a new wireless broadband access technology, is currently attracting significant attention. This work proposes a distributed medium access protocol, named Ripple, for wireless mesh networks (WMNs) under tree topology. In contrast to existing random-access approaches, Ripple uses a controlled-access approach to protect nodes from unintentional packet collisions and maximize the spatial reuse. The performance of Ripple under an error-free channel was investigated and the accuracy of the analysis was verified by simulation. Simulation results also indicated that Ripple achieved throughput, stability, and QoS enhancement than that of 802.11 DCF under a highly loaded situation in both chain and tree topologies.

The energy consumption is the most important issue in the wireless sensor network. In order to extend the lifetime of the wireless sensor network, clustering technique is considered as an effective way to achieve the power conservation, network scalability, and load balance. In this paper, we present a low energy clustering network architecture PADCP to prolong the network lifetime and to improve the performance of transceiver by adding several adaptive schemes: dynamic cluster range, dynamic transmission power, and cluster-heads re-election. Besides, our PADCP also improves the load balance when the sensor nodes are non-uniform dispersion. In addition, the mobility of the sensors is also taken into consideration in this paper. The experimental result proves that our proposed method is effective in saving power and load balance.

This work presents a power-efficient routing (PER) mechanism to identify a minimum-power path for the opportunity driven multiple access (ODMA) communication in UMTS system. Prior to the route discovery, the PER mechanism utilizes an analytical solution to predict the total power and number of intermediate UEs required in the minimum-power path. With the prediction, the PER mechanism provides a method to set the transmission power and maximum hop-count such that the power consumption of each UE during the route discovery is significantly reduced. Simulation results demonstrate the accuracy of the prediction and the required signaling of PER is dramatically reduced compared to dynamic source routing (DSR).

The integration of WLANs and 3G networks has recently evolved into a very hot topic. In order to provide a convenient access to both networks in different environments, the integration of 3G and WLAN authentication procedures would be highly beneficial. We propose a novel access control mechanism which reuses the existing 3GPP authentication procedures over a secure 3GPP infrastructure to obtain WLAN access. The proposed method, based on a loose coupling architecture, can be deployed over WLAN networks with or without IEEE 802.11x and employs a single set of control procedures for both WLAN and 3GPP accesses.

This paper proposed an architecture of the broadband mobile wireless TDMA MAC (BMW T-MAC) protocol, designed and implemented by Advanced Technology Center of Computer Communication Research Laboratories (ATC/CCL). It is modified from the GPRS standard and aimed to support the voice services and IP application simultaneously. Due to the combination of the GSM and the Internet technology, this architecture can be easily extended as a micro-cell base station for GPRS and providing services within a local area. The proposed architecture used packet-switched technology and a TDMA multiple access scheme for supporting future high-speed, multimedia services being defined by universal mobile telecommunication system (UMTS) or IMT-2000. A reference testbed is being developed to validate the effectiveness and the efficiency of the proposed BMW T-MAC.

The General Packet Radio Service (GPRS) is a standard for high-data-rate packet communications in future GSM networks. Due to the multi-tier requirements in future wireless communication systems, a mobile station needs to be able to switch in and out between an indoor pico cell and an outdoor micro/macro cell. To adapt to different transmission characteristics in different radio tiers, a new design that enables GPRS to work in low-tier TDD (time division duplex) mode is proposed. This new architecture consists of a new GPRS MAC protocol that can dynamically assign the transmission sequence so that optimal channel utilization is achieved. The performance is evaluated via simulation. It shows that the proposed architecture gives a high flexibility to GPRS in the TDD mode.

As the growth rate of the Internet subscription increases, the demand for providing wireless access for Internet applications becomes apparent. While packet data networks like CDPD, RAM, and Metricom provide Internet services, their channel capacity is generally insufficient for Internet applications such as Web browsing. Asymmetric high-speed wireless access techniques that support wide-area high-speed Internet applications have been studied and investigated extensively in the industry. However, the network architecture to support interworking of the high-speed wireless access network with the Internet has not been widely discussed. This paper addresses architecture alternatives for interworking of high-speed wireless access network, with Internet backbone for providing a seamless wide-area wireless Internet access service.

This paper proposes an architecture of the Broadband Mobile Wireless TDMA MAC (BMW T-MAC) protocol, designed and implemented by the Advanced Technology Center of Computer Communication Research Laboratories (ATC/CCL). It is modified from the GPRS standard and aimed to support voice services and IP application simultaneously. Due to the combination of GSM and Internet technology, this architecture can be easily extended as a micro-cell base station for GPRS and providing services within a local area. The proposed architecture used packet-switched technology and a TDMA multiple access scheme for supporting future high-speed, multimedia services being defined by the Universal Mobile Telecommunication System (UMTS) or IMT-2000. A reference testbed is being developed to validate the effectiveness and the efficiency of the proposed BMW T-MAC.

It is important to provide differentiated quality of services (QoSs) for multimedia services over wireless LAN (WLAN). Fairness is one of the key issues for QoS supporting. This paper proposes a method to achieve weighted fairness for two classes of service operating under the enhanced distributed coordinator function (EDCF) mode of 802.11e. A queueing model is adopted to analyze the behavior of the two classes. The analytical results were verified by computer simulation. Numerical results showed that the weighted goals are easily achieved by adjusting both the arbitration inter frame space (AIFS) and the contention window (CW).

The power spectrum of the input process explicitly contains the correlation behavior of input traffic and has a great impact on the queueing behavior of an ATM network. In this paper, we propose a power-spectrum based connection admission control scheme for ATM networks. The DC component, the average power, and the half-power bandwidth are the key factors of the input power spectrum. Here, we use a method to approximate the QoS by the result obtained from the equivalent average power. Finally, we construct an admission control table which contains the performance measure for different loads and the equivalent average power. Whether a new call can be accepted or not is determined by table lookup. Simulation results show that our proposed power-spectrum based connection admission control is an efficient control method for ATM networks.