We Americans love our smartphones. We love our tablets. We love just about every kind of mobile device out there. And for good reason—there is a ton of valuable, useful and just plain entertaining information available to us, often at the tap of a button.
But that demand does not come without its burdens. As more and more people rely on mobile devices to access the Internet, traffic across the finite amount of spectrum—the invisible radio waves that connect devices and allow us to talk, text and use mobile applications—has swelled. Like a highway, these limited radio waves are quickly becoming congested, and unless more is made available, it will begin to slow connection speeds and make service less reliable.
There are two types of spectrum: licensed and unlicensed; and we need more of both. Wireless operators have invested heavily in licensed, exclusive-use spectrum to build robust networks for their customers. But unlicensed spectrum, which is shared and has long been open to anyone, also plays an important role in meeting consumer demand. This unlicensed spectrum has long served as the platform for well-known technologies like Wi-Fi and Bluetooth.
As more Americans access data-intensive content, like mobile video, the current supply of licensed spectrum won’t be sufficient to meet consumer demand. While it will be critical to free up more licensed spectrum—which the government can do through auctions—it is also important to continue developing innovative technologies on unlicensed spectrum to help avert a capacity crunch.
There are new technologies on the horizon that will do just that: LTE-Unlicensed (LTE-U) and Licensed Assisted Access (LAA). These technologies are a combination of the best elements of Long Term Evolution (LTE)—which is the predominant licensed technology used by mobile operator—and unlicensed spectrum. As such, they will provide consumers with a fast, reliable mobile service.
Once deployed, these technologies will operate alongside Wi-Fi; they will not crowd it out, as some claim. According to recent tests, – including one conducted by Qualcomm and CableLabs – LTE-U is a better neighbor to Wi-Fi than Wi-Fi is to itself—meaning LTE-U users can share unlicensed spectrum with Wi-Fi better than another Wi-Fi use could. The results clearly indicate that gain in throughput is better when LTE-U is employed adjacently to Wi-Fi. The facts are also substantiated by industry leaders such as Nokia and Ericsson.
As promising as budding LTE in unlicensed spectrum technologies is, critics from cable and some tech giants are standing in the way.
Many tests, including a study Google presented to the FCC, acknowledge that they merely “emulate” LTE-U signals instead of using actual LTE-U technology. In any test scenario, the important things to consider are consistency of test conditions, number of transmitting nodes, radio channel fading conditions, location of User Equipment (UEs) and the mix of type of devices – Wi-Fi and LTE-U in this case. Qualcomm testing in conjunction with CableLabs’ test specifications clearly demonstrates that LTE-U shares spectrum fairly with Wi-Fi and is good a neighbor to Wi-Fi than Wi-Fi is to itself.
The LTE-U Forum, a group formed by industry stakeholders to develop technical specifications for the technology, has already outlined specific coexistence specifications in the United States. The 3GPP is working towards completing LAA standardization – expected to be completed in Release 13. 3GPP standardization has mandated the design target which specifies the LAA design should target fair coexistence with existing Wi-Fi networks to not impact Wi-Fi services more than an additional Wi-Fi network on the same carrier, with respect to throughput and latency. According to 3GPP TR 36.889 (Study on Licensed-Assisted Access to Unlicensed Spectrum), “The use of LTE in unlicensed spectrum can serve as a useful additional tool by operators to maximize the value they can provide to users, while the core of the activity of the operators remains anchored to the licensed spectrum.”
The fair co-existence of LTE unlicensed technologies and Wi-Fi is not only possible, it allows better efficiency, better indoor coverage for wireless users, and higher capacity leading to an enhanced consumer experience. U.S. carriers are eager to deploy this technology and improve users’ experience. Given the potential for such enormous gains in the consumer experience, Americans should not have to wait for this new and innovative technology any longer.
Vishal Brahmbhatt is a Radio Network Technologist who has worked in the sphere of LTE Radio Access Network (RAN) technology development and systems engineering for more than 13 years, mainly as a consultant.
Filed Under: Telecommunications (Spectrum)
