Application of 4G Technology in Mobile Broadband Design

Mobile WiMAX has become the technology of choice for 4G cellular technology. It can meet the requirements of new smartphones, mobile Internet devices (MIDs) and laptops, providing efficient broadband connections for a variety of services such as data, VoIP and video streaming with carrier-grade QoS, supporting mobile broadband needs now and even for many years to come.

Adding WiMAX connectivity to mobile products can provide broadband speeds of more than 1Mbit/s for all these services while maintaining the size and battery life of existing 3G devices. Broadband speeds are opening up markets for many new devices such as MIDs, ultra-mobile PCs (UMPCs) and mini-notebooks. WiMAX subsystems packaged in standalone modules simplify the integration of this wireless technology.

As nationwide WiMAX networks are built and costs continue to fall, more and more possibilities are becoming a reality. Consumer products ranging from cars to appliances can benefit from the use of WiMAX (Figure 1). Several WiMAX products are now available, including laptops, mobile phones, mini laptops, UMPCs, and MIDs.

Mobile WiMAX modules must include WiMAX baseband PHY components, media access control (MAC) chips, RF components and power amplifiers.

The earliest mobile WiMAX user products were USB adapters and PC cards, primarily for notebook computers. These products worked well with first-generation WiMAX base stations in metropolitan and urban areas where mobile users wanted access with higher bandwidth than Wi-Fi hotspots.

Since the introduction of the first generation of USB adapters and PC card products, the mobile wireless market has shifted its focus to mobile phones and other devices smaller than laptops. Although there is no standard definition of the various types of mobile phones, there are several terms that have been accepted by the industry, namely smartphones and VoIP phones.

Smartphones support e-mail and Internet access in addition to basic phone functions. By integrating multi-mode functions - 3G and WiMAX - and with the increasing popularity of WiMAX networks, these phones can provide users with seamless voice and data services.

At the other extreme are low-cost VoIP phones, where traditional voice communications are the primary application. WiMAX is just an optional wireless technology for wide area network connectivity. In some cases, these phones may include some other basic features, such as text messaging and very simple data transfer.

The main markets for VoIP phones are emerging countries and regions where the wired infrastructure is relatively weak and most people need voice services before other applications. Mini laptops are small notebook computers with 7-inch to 10-inch LCD screens that provide mobile Internet and email access. Typical mini laptops use Windows or Linux operating systems and support application software similar to laptops, but at a lower performance level.

Wi-Fi and other connectivity technologies are now standard, and future mini-notebooks will also add WiMAX. UMPC is a mini tablet computer developed by Microsoft and Intel, with a 4-inch to 8-inch touch screen. Most UMPCs run the Windows XP Tablet operating system and cost less than $1,000. UMPCs are common in vertical professional markets, such as the medical and restaurant industries. MID is the first small portable device launched by Intel, slightly larger than a smartphone, but smaller than a mini-notebook or UMPC.

The purpose of MID is to provide the best mobile platform, which can not only realize Internet access and email access, but also support multimedia applications. Although it is very attractive from a technical point of view, it remains to be seen whether consumers are willing to carry a third device after carrying a smartphone and a laptop.

Technical requirements

Wireless handset designs are becoming increasingly complex as consumers expect a wide range of features from their mobile products. Devices must support many wireless options, such as Bluetooth for connecting to headsets, Wi-Fi for connecting to home or wireless hotspots, and wide area network connections such as 3G for connecting to mobile networks. At the same time, consumers want longer battery life without adding weight or bulk. Since WiMAX is the first 4G technology on the market, handset manufacturers are actively adding this new functionality.

The way product designers integrate WiMAX will help determine whether a particular device achieves the various features and is proven to 'really meet' market needs.

Choose the right WiMAX module

One way to ensure that mobile products offer maximum functionality is to leave space for wireless modules that meet market requirements. By designing the device as a module, mobile device vendors can support a wide range of wireless technologies. Today, a standalone module measuring approximately 20mm x 20mm can support all the requirements for mobile WiMAX certification and can be added to new products.

Such modules must meet numerous technical requirements, including suitable form factor, low power consumption, support for multiple frequency bands and high throughput. In addition, the module must not affect the performance of other wireless devices in the mobile product.