## 1 Introduction  
High-speed access to mobile data has become one of the most significant demands of smartphone subscribers. The increasing availability of intelligent equipment and the ever-growing demand for multi-media streaming services have drastically increased the volume of mobile data traffic [1]. In 2016, the total generated mobile data was 8.8 Exabyte, 50% of which belonged to video content. It is estimated that this amount will reach 71 Exabyte in 2020, 75% of which will belong to video content [2]. Network operators have spent lots of R&D costs on providing better data. Therefore, it has led to the significant expansion of mobile broadband. Statistics and figures indicate that the mobile broadband subscriber growth rate has been steadily higher than that of fixed broadband in the world. A fixed broadband penetration rate reached 11.9% in 2016, from 0.9% in 2012, while mobile broadband penetration rate reached 49.4% in 2016 from 21.7% in 2012 Figure 1. Like other countries [3], in Iran, mobile broadband penetration rate has been much higher than that of fixed broadband, as the growth rate of fixed broadband subscribers has moved from 2.81% in the summer 2012 only to 12% in the spring 2017, while the growth rate of mobile broadband subscribers has shifted from 1.92% in summer 2012 to 42.5% in spring 2017 Figure 2.  
Cellular network technologies, like the third generation (3G) and fourth-generation (4G) of mobile networks, have considerably contributed to the development of mobile broadband. 3G technology was developed during the 90s and entered the global market in 2002. This technology was becoming widespread in 2007. Actually, in December 2007, 190 operators in 40 countries provided 3G services to their subscribers. In Iran, Rightel operator, which was established in 2007, received the 3G service license in January 2010, but it started its work in June 2011. Therefore, 3G mobile networks entered the market with a delay of 9 years. The commercialization of 3G in the country coincided with the commercialization of 4G in the world. The 4G technology was launched in September 2014 by the Irancell operator. Afterwards, Mobile Telecommunication Company of Iran (MCI) and Rightel started 4G mobile networks. Limitations such as mobility, low-rate of transmission, and bandwidth constraints were among the most important reasons leading mobile operators to go to launch 4G mobile networks. Figure 1: Comparison of the penetration rate of mobile broadband subscribers with that of fixed broadband subscribers in the world from 2012-2016 (Source: ITU [4]). Figure 2: Comparison of the penetration rate of mobile broadband subscribers with that of fixed broadband subscribers in Iran from 2013 Q3–2017 Q2 [5]. According to specifications detailed by IMT-advanced, any 4G mobile network should meet the following minimum requirements [6]:  
* It should be completely based on Internet Protocol (IPV6)
* For high mobility communications such as from cars and trains, data transmission rate should be 100 megabits per second (Mbps), and for low mobility communications such as pedestrians and stationary users, data transmission rate should be 1 gigabit per second (Gbps)  
As the most prominent representative of 4G, Long Term Evolution (LTE) technology has become very popular. LTE was developed in 2004 and commercialized during 2010-2011. LTE, which is often marketed as 4 GLTE, is a standard for transmitting high-speed wireless data for data terminals and mobile devices. LTE is based on GSM/EDGE and UMTS/HSPA technologies, which have greatly enhanced the capacity and speed via a different radio interface, together with core network improvements. LTE standard has been developed by the 3 rd Generation Partnership Project (3 GPP). Differences of mobile telecommunications technologies (MTTs) have been presented in Table 1.  
Several studies have shown the widespread market share of LTE in the next five years so that if mobile operators cannot properly manage this technology, they will eventually lose much of their subscribers' market share.