## 2 Broadband System
### Mobile Network Evolution
Moreover, the combination of EDGE and GPRS results in a potential system comparable with the International Telecommunication Unions IMT-2000 perception [201; 209]. * 3G Mobile Systems: The 3G network development presents the right phase for high-quality mobile broadband (MBB) service delivery. Consequently, mobile operators have upgraded their networks to 3G technology to offer several broadband applications with fast wireless internet access to various subscribers. For instance, operators with GSM have evolved their networks to 3G through high-speed packet access (HSPA) and UMTS deployment. Moreover, the traditional operators with CDMA solutions have deployed 1x EVolution data optimized (1x EV-DO) for the system upgrade to the 3G network. However, the presented 3G solutions are only capable of delivering data throughput between a few hundred kbps to a few Mbps [159]. HSPA and 1x EV-DO are discussed in the following enumeration. * HSPA: To start with, High-Speed Downlink Packet Access (HSDPA) is defined in the Third-Generation Partnership Project (3 GPP) UMTS Release 5 specifications as a DL-only air interface. It can effectively support a peak user data rate of about 14.4 Mbps with a 5 MHz channel, depending on the number of the employed codes. For instance, when 5 codes are used, HSDPA can offer peak data rates of about 3.6 Mbps; however, with 10 codes, it can give peak rates of about 7.2 Mbps. Furthermore, typical average rates by the subscribers are between 250 kbps to 750 kbps. Note that the basic HSDPA system performance can be considerably improved by employing schemes like spatial processing, multiuser detection, and diversity reception. In addition, the High-Speed Uplink Packet Access (HSUPA) is a UL version of HSDPA standardized in the 3 GPP Release 6 (feature for WCDMA) specifications. It is not only based on the support for about 5.76 Mbps UL data rates, but also on capacity and throughput increase [210]. Besides, HSUPA aims at reducing the associated latency [211]. The combination of HSDPA and HSUPA technologies is known as HSPA. Therefore, it aids in packet data transfer optimization in the DL and UL. Note that HSPA also helps in enhancing UMTS network capacity for data transmission and offers considerable latency reductions [159; 210; 211; 212]. Furthermore, in the 3 GPP Release 7, 8, 9, and 10, additional enhancements to the HSPA have been specified in the context of HSPA evolution (HSPA+). The main goal is to improve the HSPA-based radio network performance regarding the peak data rate, spectrum efficiency, and latency [213]. This is to deliver a system with performance that is comparable to that of LTE in a 5 MHz carrier and as well as backward compatible with earlier releases [214]. * 1x EV-DO: The 3 GPP2 standards organization-defined 1x EV-DO as a high-speed data standard, which is an evolution to second-generation IS-95 CDMA systems. A peak DL data rate of 2.4 Mbps can be supported in a 1.25 MHz channel. Typically, the subscribers can experience average download throughputs between 400-600 kbps. Similarly, average upload throughputs of about 500 to 800 kbps, with low latency can be achieved. In the 1x EV-DO Revision A and B versions, a peak rate of 3.1 Mbps and 4.9 Mbps, respectively, can be offered to the mobile user. Furthermore, both versions can offer UL data rates of about 1.8 Mbps. In addition, it should be noted that, Rev. B has optional support for higher channel bandwidth operations [159; 216; 215]. For instance,about 73 Mbps and 27 Mbps in the DL and UL, respectively, can be achieved when operated at 20 MHz [159]. Typically, in a 3 carrier deployment, Rev. B can deliver a peak rate of 14.4 Mbps. Furthermore, there has been a notable evolution in the 3G systems to support multimedia services [215]. A good instance is the 1x EV-DO Rev A that supports video and voice telephony over IP [159]. An additional step in this technology is based on the development of 1x EV-DO Rev. C that is also known as Ultra MBB (UMB).