# A Pervasive Collaborative Architectural Model at the Network's Periphery
## 2 Related Works on Pervasive Architectural Models and Their Limits
### Issues of Pervasive Architectural Models at the Periphery of a Network
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**Architectural Model** & **Description and Analysis of These Models** \\ \hline Mobile edge computing (MEC) & The main advantage of MEC is to deploy mini cloud servers in each communication base station, especially at the edge of mobile networks. MEC is applied to mobile devices in these edge networks to reduce delays by allowing computational and storage capabilities at the edge of mobile networks instead of being at central servers [5, 31]. MEC has better discharge techniques to edge servers, giving the network low latency and high bandwidth [6]. In addition, it provides efficient storage and energy consumption through many architectures such as the software-defined system for mobile edge computing (SDME) for storage [32] and ME-VoLTE for computing, which integrates MEC with long-term evolution (LTE) [33]. \\ \hline Cloudlet & A cloudlet is a proximal cloud that brings computing capacities closer to the mobile devices it serves to avoid latency. A cloudlet is formed by a cluster of multi-core computers, a very powerful multi-core server and a high bandwidth wireless LAN with high connectivity [34, 35]. “Cloudlets are decentralized and widely dispersed Internet infrastructure whose compute cycles and storage resources can be leveraged by nearby mobile computers [34].” \\ \hline Collaborative fog computing (CoFog) & CoFog provides dynamic services based on predefined templates using formal mechanisms called operations. An operation represents a relationship between a collaboration request and the services that can fulfill that request. There are two types of operations: conservative, which retains the same type of data, and non-conservative, which creates a new type. CoFog relies on the ability to discover, recover and provide security services using role-based and attribute-access models [19]. \\ \hline Mobile cellular cloud architecture (MoCCA) & MoCCA [29, 36] uses small scale micro-serves loaded on mobile phones to build its own mobile cloud architecture. Its resources are smartphones, base stations, base station controllers and mobile switching centers. Its main concerns are architecture (MoCCA) (i) comcufficiently, (ii) computational limitations, (iii) churn, because of user mobility and device volatility, (iv) lack of power; and (v) user incentives. \\ \hline mClouds & With mClouds [29, 37], mobile devices become essential components of cloud computing architectures. An mCloud uses specific resource-discovery procedures, incentive management and distributed processing to execute locally whenever possible. \\ \hline MobiCloud & MobiCloud [29, 38] is a trustworthy collaborative mobile cloud administration system that enables the efficient and collaborative management of mobile smart phone resources. Its objective is to use mobile devices even when there is no internet connectivity. MobiCloud architecture has participant nodes and a field control node (a cloud agent) that provides centralized cloud controller functionalities by locating the required resources. \\ \hline Mobile cloudlet (M.Cloudlet) & M.Cloudlet uses its own servers without base station services to provide cloud services in order to dispense the connection to remote cloud central servers or central ones of fixed cloudlets. To build a network of mobile cloudlet, M.Cloudlet uses Wi-Fi Direct to connect nearby mobile devices [39]. The M.Cloudlet architecture has two main phases: (i) build M.Cloudlet by discovering and negotiating neighboring devices to form their groups and choose their owners, then exchange information, (ii) control and manage devices, including their tasks and spontaneous lists of participating devices [39]. \\ \hline Multi-group networking & This supports Wi-Fi Direct connections between multiple devices in groups, then interconnects different groups to create ad hoc multi-hop networks. However, the Wi-Fi Direct standard [40] defines only intra-group communications, where the group owner (GO) is central to all communications in its group. A Wi-Fi Direct device called a gateway node can operate as a member of more than one group at a time. In a proposed time-sharing mechanism, the gateway node can switch between two or more groups to implement multi-group communication scenarios using only Wi-Fi Direct [41]. \\ \hline Building smart multi-group networks by Wi-Fi Direct & Independent group formation aims to achieve the efficient use of devices while maintaining connectivity. The main obstacle to the widespread adoption of P2P communication is the lack of coordination of services. Efforts are focused on the potential of Wi-Fi Direct as a P2P communication technology in medium- and large-level frameworks using unrooted Android devices. It functions by (i) designing multi-groups interconnected logical topology by tunnelling the application layer and (ii) proposing a fully distributed intelligent group formation mechanism to construct networks, considering the group’s durability, the devices’ power consumption, the bandwidth average and network extent [42]. \\ \hline Mobile ad hoc cloud computing (MAC) computing (MAC) & MAC computing “is still in its infancy” [29]. Several definitions of MAC have been proposed [43, 44, 45], such as “MAC enables the use of many nearby resource-rich mobile devices to provide computational services in the vicinity” [45]. MAC roots are in mobile cloud computing (MCC) but also in opportunistic computing [43] or distributed computing with the caveats of intermittent connectivity and delay tolerance. The ad hoc cloud features are developed by [PERSON] et al. [46] as self-administration in terms of flexibility, performance and balancing potentially contradictory policy goals. MAC challenges include (i) limited computing and energy resources of mobile devices and their ability to perceive context and location, (ii) network connectivity, (iii) security and (iv) partitioning and application loading. In addition, there are specific challenges, as shown in Figure 1, introduced in the MAC context as mobile devices are the only resources [29]. \\ \hline \hline \end{tabular}
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