EMMM: Energy-efficient mobility management model for context-aware transactions over mobile communication

Highlights

• The proposed model reduces the dropping and failure rate of HRT request that has direct impact on the QoS of mobile communication during roaming.

• Combination of queuing models improves channel utilization and decrease the blocking rate of NTR request.

• Inclusion of contextual information in the proposed model has enhanced the throughput of context-aware transactions.

Abstract

The rapid advancements in wireless technology and enhanced computing power of handheld devices, enable the users to perform transactions anywhere, anytime during roaming. Carrying out ongoing transactions during roaming is a crucial field for research in the field of mobile communication. In order to ensure a high quality of service (QoS), an energy-efficient handover process is essential for accomplishing the ongoing transaction. The performance of mobile communication is mainly deteriorated by the roaming and low battery power requirement of mobile host. Due to limited channel availability, most of the handover requests are failed. Energy-efficient enhanced mobility management queuing model is proposed by combining two existing schemes GE/GE/C/N/FCFS and scheme GE/GE/C/N/PR to strengthen the performance. In this research, EMMM scales down the dropping rate of handover transaction request (HTR) and new transaction request (NTR).The proposed model has achieved the enhancement of channel utilization along with the reduction in handover failure and low drop and blocking rate of HTR and NTR, respectively.

Introduction

The high computing and storage capacity of handheld gadgets have increased exponentially in parallel with next-generation (4G/5G) wireless technologies. The idea of getting to and processing information moves from fixed to versatile, which encourages users geologically autonomous known as a mobile data framework. Today, it is in high demand due to its pervasive nature of anytime and anywhere connectivity. Mobile communication framework confers opportunity of roaming during execution of transaction. The geological region is partitioned in small service area to efficient use of frequency, which is known as a cell. Fixed host (FH), base station (BS), mobile support station (MSS) and mobile host (MH) are the pillar of mobile communication [1], [2]. FH used as permanent shareable data repositories and linked via high speed wired network infrastructure. MH can store a constrained measure of data. It may move or be fixed. BS or MS provides services to the MH which roam in that base station. The mobile communication framework is delineated in Fig. 1.

Handover is the way of transferring the ongoing transaction request from current BS to a new BS during roaming. Transferring of ongoing transaction requests may cause the change in point of connection during the communication [1], [3]. A handover mechanism maintains a network connection as portable devices roam from one BS to another. It can also modify its access point of a network [4]. Hard-handover and soft-handover are two broad categories of handover process based on pint of connection. Handover process is shown in Fig. 2 [5]. High mobility and small cell size lead to several issues such as frequent handover (HO), unnecessary HO and ping-pong effect. These effects cause an increase in communication latency and energy consumption during communication, along with a reduction of QoS. Then, the handover process should be activated at the right instant of time and transfer access control to the new selected optimal BS to moderate these impacts. According to the network technology, handover is of two types, namely horizontal handover and vertical handover. Handover technique in which, radio access technology (RAT) of current and target BS which both are the same, known as horizontal handover, and if current and target BS both have different RAT then they are called vertical handover. Another classification of handover based on the point of access during the handover process is of again two types; hard handover and soft handover. If a MN is associated with both points of access (PoA) during handover execution stage, then it is called soft handoff or make-before-break. But, if a MN is connected only one PoA at the time of handover execution phase, then it is called break-before-make or hard handover. In general, the entire handover process involved three phases, namely decision, radio link transfer and channel assignment. In the decision phase, the MN collects contextual handover parameters such as RSSI, SNR, latency and other information of all neighbouring BSs for reporting to its current serving BS. Then, the current serving BS of MN can decide to trigger a handover and pick out the most appropriate optimal available BS as target BS. In the radio link transfer phase, the MN transfer connection from the current serving BS to targeted BS through either hard or soft handover mechanism. Finally, the channel assignment phase handles allocation of channel resource.

The steps in handover are as

• BS1 persistently makes an impression on mobile host, that is utilized in execution of transaction.

• Mobile host obtains message from BS1 and decides whether it is in BS1 or BS2.

• If mobile host is in BS1, then no need to initiate handover procedure and run transaction which continues seamlessly. Mobile host processes through the condescension given by BS1.

• If MH finds it in BS2, then the MH requires new channel in the BS2 to continuous execution of the ongoing request. It asks additionally to render its new address to BS1.

• When user leaves BS1 and get registered in BS2, all contextual information and data regarding ongoing context-aware transaction are redirected to BS2 from BS1.

The context-aware transaction can be interpreted as anywhere and anytime mobile communication transaction. mobile communication transaction provides a flexible new open digital platform in which devices and services are context-aware [6]. Any information that can be used to describe the situation of people, source and service in a service-oriented environment is called Context [7]. Therefore, context-aware systems are systems that automatically adopt their operation according to the environment by considering contextual information such as location, time and users’ needs and environment parameter. Context-aware transaction $({\mathrm{CA}}_T)$ is formally defined as “$T_i$ which is a triblet $〈F,L,\mathrm{FLM}〉$; where $F=e_1,e_2,e_3,\dots ,e_n$ is a set of execution fragments, $L=l_1,l_2,l_3,\dots ,l_n$ is a set of locations, and $\mathrm{FLM}={\mathrm{flm}}_1,{\mathrm{flm}}_2,{\mathrm{flm}}_3,\dots ,{\mathrm{flm}}_n$ is a set of fragment location mapping where $\forall j,{\mathrm{flm}}_i\left(e_{\mathrm{ij}}\right)=l_i.$ An execution fragment $e_{\mathrm{ij}}$ is a partial order $e_{\mathrm{ij}}=\left\{{\sigma }_j,{\le }_j\right\}$ where ${\sigma }_j={\mathrm{OS}}_j\cup \left\{N_i\right\}$ where ${\mathrm{OS}}_j={\cup }_k{O}_{\mathrm{ik}},O_{\mathrm{jk}}\in \left\{\mathrm{read},\mathrm{write}\right\},\mathrm{and}{N}_j\in \left\{\mathrm{Abort},\mathrm{Commit}\right\}.$ For any $O_{\mathrm{jk}}$ and $O_{\mathrm{jl}}$ where $O_{\mathrm{jk}}=R\left(x\right)$ and $O_{\mathrm{jl}=}W\left(x\right)$ for data object $x$, then either $O_{\mathrm{jk}}{\le }_j{O}_{\mathrm{jl}}$ or $O_{\mathrm{jl}}{\le }_j{O}_{\mathrm{jk}}$”. Then, informally context aware transaction can be defined as ${\mathrm{CA}}_T=\left({\mathrm{cst}}_i,<\right)$, where $1\le i\le n$; $n$ is the number of component service transaction in a ${\mathrm{CA}}_T,{\mathrm{cst}}_i$ Component service transaction. It is executed to acquire the anytime, anywhere context information for mobile services where $\left({\mathrm{MS}}_i,<\right)$ is a partial ordering of ${\mathrm{cst}}_i$. It determines the order of execution of ${\mathrm{cst}}_i,{\mathrm{cst}}_i=({\mathrm{operation}}_i,{\mathrm{context}}_i)$. The context-aware transaction can access different types of services that are distributed anywhere. In our proposed model, the context-aware transaction is represented by ${\mathrm{CA}}_T$. The essential components of the context-aware system architecture are as main coordinator $(\mathrm{MC})$, component coordinator $({\mathrm{CC}}_s)$ and mobile services $({\mathrm{MS}}_i)$. Referring to Fig. 3, we consider $\mathrm{MC}$ and $\mathrm{CC}$ that cab be deployed in FH and $({\mathrm{MS}}_i)$ which may be deployed in FH or MH. MC and CC are deployed at FHs because it is more reliable than MH [10]. Context-aware transaction requests are divided as HTR and NTR. HTR transactions are executing a context-aware transaction that is generated by moving users from one BS to another BS during the transaction. NTR requests are newly generated context-aware transactions. The requests which are generated by the user within a BS are known as the NTR.

The roaming of users degrades the efficiency and performance because, if all channels are allocated in target BS at the time of the handover process, ongoing transaction may drop. The dropping of running transaction occurs because of deficiency of free channels. The dropping of an ongoing transaction requests hamper productivity and performance. The demand for massive handover processes creates unnecessary system overhead due to real-time movement and bandwidth limitations of MH which make network unstable and cause frequent disconnections. Low battery backup and storage capacity delimite functionality of MH. ${\mathrm{CA}}_T$ does not adhere tradition database system atomicity, consistency, integrity and durability. Therefore, context-aware transactions need to satisfy new set characters. Relaxed Atomicity, Consistency, Context and Durability (RACCD) are a new modified set of properties that fulfill the requirement of mobile context-aware transaction [8]. To Improve the QoS of mobile transaction communication system, an efficient and enhanced handover technique is essential to reduce network overhead, dropping of handover and failure of handover with ensuring seamless connectivity. We have come up with an enhanced energy-efficient mobility management model for context-aware transactions over mobile communications (EMMM) for mobility management to improve the QoS in context-aware mobile transaction framework.

In the remaining part of the paper, Section 2 has some substantially related works related to our work. Section 3 describes the GE distribution. Section 4 has proposed model description, algorithm along with analysis. Section 5 clarifies simulation and results analysis, and the last segment has inference with scope and possibility of future work.