HSPA +/LTE introduction strategy (1)

From the ancient taima Road to the highway, from the fire to the use of solar energy, from the advent of the Flying Pigeon book to the emergence of instant messaging technology, technology has been serving human life. When the use of the Internet is deeply rooted in the hearts of the people and people are no longer satisfied with simple voice communication, the combination of the Internet and mobile networks has become a new impetus for the development of wireless communication technology.

As the number of Internet users on mobile phones rapidly increases, mobile operators are constantly developing new data services: online multimedia such as online music, online reading, and online streaming media) mobile instant messaging and information push services, such as mobile phone reports, mobile phone mailboxes, and convenience services. Through the perfect combination of broadband data services and mobile communication networks, carriers try to implant successful data service applications on PCs into mobile terminals and explore new markets for data service applications, attract Internet users to transform to mobile broadband users, thus increasing the market share of mobile operators.

With the deployment and commercialization of HSPA networks around the world, broadband data services have been applied in the global mobile market. However, the introduction of high-speed data services, especially video, music, games, and other business sources, constantly puts forward new requirements for mobile networks. Therefore, how to obtain a higher rate and a larger system capacity, A more perfect user experience is now the focus. With the development of the mobile broadband market, HSPA + and LTE have become the focus of attention in the industry, and the commercialization process is accelerating, next, we will discuss the introduction of HSPA +/LTE strategies to 3G networks in China.

Technical Revolution brought about by HSPA + and LTE

HSPA + is the enhancement and evolution of HSPA. From a technical perspective, "+" means the improvement of modulation, antenna, and other wireless technologies. As a technology that evolves to the fourth generation of mobile networks, LTE introduces more new technological innovations.

Naturally, the first new technology to be considered is how to increase the network capacity and service download rate. HSPA + and LTE share a common feature in improving the speed, and there are also differences between different standards, however, they have all made a qualitative improvement in the bandwidth of wireless mobile networks. In particular, LTE can already be comparable to fixed-line broadband.

Key technologies for improving system capacity

MIMOMultiple-Input Multiple-Output) is a key technology used by HSPA + and LTE. Its basic principle is that Multiple antennas are used at the transmitting end and the receiving end, multi-antenna is used to suppress channel fading. without increasing bandwidth and antenna transmission power, the channel capacity and spectrum utilization are improved, the channel reliability is improved, and the error rate is reduced. Therefore, MIMO technology can improve system capacity through channel multiplexing, and also improve channel transmission quality through diversity gain. In 3GPP, multiple MIMO application solutions are standardized. For different application scenarios, the system can flexibly switch between different MIMO solutions based on changes in the user's application environment.

Another effective method to increase capacity is to adopt an efficient modulation mode. The HSPA + downstream link can adopt 64QAM modulation, And the uplink supports 16QAM modulation. In terms of downlink, the modulation efficiency of 64QAM is 50% higher than that of 16QAM, and the peak rate of a single user can reach 21.6 Mbps. When 64QAM and MIMO are used at the same time, the peak rate of a residential area can reach 43.2 Mbps. In order to match the uplink rate with the downstream data rate, The HSPA + system introduces 16QAM modulation for HSUPA. After using 16QAM technology, the uplink peak rate can reach 11.5 Mbps. LTE uses OFMD modulation technology to support flexible bandwidth configuration and spectrum allocation mechanisms, resulting in higher peak rates. In the case of 20 mbps bandwidth of 2x2 MIMO, the downlink peak speed reaches 150 Mbps and the uplink speed reaches 50 Mbps.

In addition, there are also a variety of technologies to increase system capacity, such as MC HSPAMulti-Carrier HSPA) multi-Carrier technology, so that the base station can receive/send data in parallel in the Upper/lower dual-cell or even multi-cell, coupled with 16QAM, 64QAM, MIMO, and other technologies, the service can support up to 23 Mbps/downstream peak rate of 86Mbps, providing users with a higher speed experience. For a large number of applications of grouped data businesses, the continuous grouping connection CPC technology can reduce the occupation of system resources by online users, support more users online for a long time, and improve the system utilization.

Flat architecture and Intelligent Network

For better compatibility, HSPA + basically follows the HSPA network architecture, while there are new changes in the LTE system. First, the wireless access system has only one network Node: eNode B, which replaces Node B and RNC in the 3G network. The X2 interface is introduced between eNode B and eNode B, some of the business traffic can be directly processed between the base stations without being sent to the core network, greatly improving data processing efficiency. The core network nodes of LTE are also simplified, and the network performance is further improved by flattening the network.

As we all know, wireless network sites are scattered and there are a large number of sites. Therefore, network activation, network configuration, network optimization, and network maintenance work are very complicated and become the main component of operator operation and management costs. In addition, the wider the network coverage, the dramatic increase in costs. Therefore, SON technology is introduced in LTE, namely, "Self-Organizing Network", which has four functions: Self-configuration, self-optimization, self-healing, and multi-carrier shared management, it can realize automatic configuration of wireless neighboring areas, fast fault recovery, real-time detection of network devices and KPI reporting, user and device tracking and other network self-management functions, greatly reducing the workload of manual configuration and maintenance networks, reduce operators' OPEX costs.

How to deal with the arrival of the HSPA +/LTE era in Wireless Access networks?

IP-based network to cope with data surge

With the development of the HSPA market, introducing PC-based data services into mobile terminals has become a major trend in the development of mobile broadband services. Classic applications in fixed data networks such as advertising and search services, it will become a potential business of the mobile broadband market. The HSPA + and the next phase of LTE technology will inject a stronger driving force into the mobile broadband market-faster service rate and better QoS performance, it also supports users' long-term online features, creating a unique advantage for the system to carry broadband services. This also determines that HSPA + and LTE Wireless Access networks must have extremely high data throughput capabilities to meet the needs of large-scale broadband applications.

First, regardless of HSPA + or LTE, its wireless access network should be "IP-based network elements", that is, RNC, Node B, eNode B is built on the full IP hardware platform and provides external IP interfaces. At the same time, the software supports the full IP/ATM protocol stack to achieve mixed transmission from ATM and ATM/IP, the smooth transition to full IP transmission will ultimately carry high-speed wireless data services on the whole IP network.

Secondly, HSPA + and LTE require IP-based transmission networks. In addition, LTE requires a more flat IP transmission network architecture. At the same time, after the X2 interface of the LTE system is introduced, the transmission network architecture also needs to be adjusted to adapt to the Mesh network structure of LTE. LTE imposes higher requirements on the end-to-end latency of transmission networks, and the IP transmission network must provide higher QoS indicators. In terms of security, due to the openness of the IP network and the plaintext transmission characteristics of LTE on the S1 interface, the IP transmission network is required to provide corresponding security protection, which puts forward new requirements for the design and deployment of the transmission network.

Software upgrade to protect existing investments

In fact, The HSPA + was created to make The HSPA network evolve at the lowest possible cost to improve system performance, tap the WCDMA network potential, and protect operators' investment, at the same time, to ensure the continuity of the user's use of network services. Based on this goal, most HSPA + technologies can be upgraded through software to achieve MIMO, which maximizes the purpose of protecting existing investments.

Using the HSPA network deployed by the ZXSDR 8000 Series base stations of ZTE, you only need to upgrade the software to implement the features of HSPA + in various stages, and achieve smooth evolution to HSPA +, it not only minimizes the cost of system evolution, but also does not affect the business operations of the current network. In Romania, ZTE used less than one month to upgrade the HSPA System of ZAPP without affecting the current business, the help of ZAPP released The HSPA + commercial network, which made the Romania mobile data business leader seize the lead again and launched Romania and even Eastern Europe.