Energy efficient scheduling in 4G smart phones for Mobile Hotspot application

Abstract

With higher data rates becoming reality, there are quite a few Internet sharing applications that are increasingly becoming popular on present day smart phones. These applications are very useful and are widely popular by names such as Mobile Hotspot, Tethering, and MiFi etc. Using these applications, multiple users (such as friends, family members and colleagues in a limited area) can share Internet from a single high speed wireless network link. Typically in this method, a mobile device (smart phone or dongle) connects to backbone network using communication networks such as 4G/HSPA+ etc. which provides high speed data link and mobile phone in turn acts as a local Internet access point for other devices using communication technologies like Wi-Fi/Bluetooth. Wi-Fi access points were originally designed to be operated as standalone devices connected with a power supply and hence no specific care was taken to save power of base stations. Though subsequent enhancements were made in specifications to incorporate power saving mode in Wi-Fi Technology to optimize power consumption of the clients, Mobile Hotspot applications does not come under the purview of such enhancements. Due to this, present day Mobile phones which run on battery and host these applications for acting as Wi-Fi Hotspot, demonstrate very poor battery life. We have performed few experiments with commercially available products, which show that technologies like LTE (Long Term Evolution) which act as the backbone for these mobile hotspot applications consume very high power. Together LTE & Wi-Fi are draining Mobile Station current at alarming rate. Effort of this work is to strike a balance between maximum achievable QOS (Quality of Service) for end users and increased battery life of mobile phone which is acting as WiFi access point. This can be achieved by efficiently coordinating power saving techniques provided by LTE/3G wireless communication specifications and those provided by Wi-Fi specifications.