# Energy-Efficient Hosting Rich Content from Mobile Platforms with Relative Proximity Sensing
## 2 Related Work  
In an attempt to meet the demands of an interactive mobile services for sharing of rich content, many studies have been performed and commercial services are launched. In this section, we present some of the related work in line with these trends. Commercial products, such as _ShoZu_[18], make it easy to upload content from a mobile to social networking or content distribution sites, such as _Instagram_[2], _Facebook_[3], and _Youtube_[19]. However, they do not provide a mechanism to discover content shared by nearby mobile devices, or mobile devices at a specific location. _uLocate_'s service, called _WHERE_[20], allows users to geo-tag a photo uploaded to the web server. _Twitter_[4] and _Xumii_[21] enable mobile users to share content with their social network, just as they would communicate with them using their PC. However, they too do not have a concept of location of the tweeting phone. _Twitter_ announced that tweets can be geo-tagged with the location of the phone. However, the details of this system are unknown. Mobile Web Server (_MWS_) powered by Symbian [22] allows mobile phones to host a web server. The content of the web site can be accessed from a server on the Internet, which redirects the http requests to the mobile phone. The motivation of _MWS_, instead of hosting on the server, is that the server might be expensive when sharing only with a few people, for example, the family members. Similar to _MWS_, _T-Wing_ enables mobile devices to host content. However, _T-Wing_ is targeted to allow anyone to access the website while providing a richer experience to nearby mobile devices enhanced with 'on-demand' Wi-Fi connection to nearby mobile platforms. From the energy efficiency perspective in mobile network, many studies have been performed. In [13; 14], the authors compare the energy consumption of LTE, Wi-Fi and aggregate interface on a mobile device. Their results show that Wi-Fi consumes around 20% of LTE's energy, and aggregate interface consumes 57% of LTE's energy for a download of 8 MB of data. In [15], the authors study energy consumption of YouTube for mobile devices. The authors present a measurement study of YouTube's energy consumption characteristics for network access technologies such as WCDMA and Wi-Fi. The results show that during a progressive download of content over Wi-Fi consumes around 40% of energy consumed by cellular WCDMA. Although the actual power consumption may be changed in accordance with the usage of a specific network technology, the difference in energy efficiency among the heterogeneous network technologies makes this work more useful [13; 14; 15]. In efforts to obtain behavioral patterns, many studies are being carried out for determining user context [23; 24]. They attempted to recognize activities using a single three-axis accelerometer worn near the pelvic region and formulated the activity recognition as a classification problem. Google Play Services [25] provides special APIs for activity recognition, which returns the user activity. In this work, we incorporated the previous studies [23; 24] into our system as an underlying context-aware mechanism. Micro-Blogs[26] presented a social network framework for mobile devices to share blogs and content with phone users around a location. Information about the phone and their location is stored in a central server over the Internet. The server has a web front end over which users can query phones around a location. Sensing as a service (S\({}^{2}\)aaS) [27] is to provide sensing services using mobile phones via a cloud computing system. They identified unique challenges of designing and implementing the S\({}^{2}\)aaS cloud. However, this work mainly focusses on cloud computing model interacting with mobile devices to provide various sensing services using mobile devices for a large number of cloud users. SOR [28] presents a vehicular social network to enable social communications and interactions among users on the road during their highway travels.