OnQ Blog

You Know LTE/LTE Advanced... But How About in Unlicensed Spectrum? [w/video]


Qualcomm products mentioned within this post are offered by Qualcomm Technologies, Inc. and/or its subsidiaries.

At Qualcomm we strive to "think of the unthinkable, solve the impossible." The newest addition to an impressive list of such feats is what we announced yesterday at our Analyst Day meeting in New York—Extending LTE Advanced to unlicensed spectrum.

You might ask "What? Why?" Well, stay with me here, I am sure you have known or experienced the roaring success of LTE, as well as its excellent user experience and high performance. You might have also heard about the popularity of offloading mobile data traffic to unlicensed spectrum using Wi-Fi. There are many ongoing efforts to streamline the interworking between 3G/4G to make the offload seamless. Qualcomm took this to the extreme by bringing the basic tenets of LTE—high efficiency and robust mobility—to bandwidth-rich unlicensed spectrum. That explains the "What?"

Now let’s look the "Why?" Consider the length that operators are going to address increasing data traffic with small cells and utilizing all spectrum assets being at the top of their agenda. Wouldn’t it be ideal for them to deploy small cells that support LTE not only in their regular licensed spectrum but also in unlicensed spectrum? Mind you, they can leverage their existing core network to make this happen. So, instead of managing two separate networks for licensed and unlicensed spectrum, and dealing with the complexities of interworking between them, they will have one unified network accomplishing the tightest possible interworking. How cool is that?

Okay, the operators are covered. What about the mere mortals like us, the users? Well, remember all the juggling between LTE and Wi-Fi networks; making sure you are connected, and connected to the right technology to get the best speed; worries about the media not seamlessly moving over between the networks, and tolerating video freezing, breaks, restarts etc.? All of that will be over with LTE Advanced in unlicensed spectrum (for the operator network). Because it’s one network, with an anchor in the highly reliable licensed band, you are always in safe hands. Add to that carrier aggregation, across licensed and unlicensed bands, and you, the user, get higher data rates and an enhanced broadband experience.

This is all good, but one natural question someone might ask (we asked it ourselves) is, "will it affect the Wi-Fi networks out there now?" Well, LTE Advanced in unlicensed spectrum has been carefully designed to protect Wi-Fi, so that both can co-exist harmoniously. So, when an operator switches from Wi-Fi (“carrier Wi-Fi” as it is called in the industry) LTE in unlicensed, not only do LTE Advanced users in the unlicensed spectrum benefit but also, in many cases, the neighboring Wi-Fi users.

Moreover, LTE Advanced in unlicensed can be brought to fruition in countries such as the United States, Korea and China using the existing standards (Rel 10) and, of course, by leveraging the existing LTE core networks.

As evident, we have been working on it for some time. Look, we even have a new webpage! We have a lot more to share and discuss and my future blogs will go into the details. If you can’t wait, go to the webpage.

Engage with us on


Prakash Sangam

Director, Technical Marketing

More articles from this author

About this author

Related News


Cellular V2X is gaining momentum

Believe it or not, the idea of talking cars on our streets and highways everywhere just got one step closer to reality.

Yesterday, the 3GPP announced the completion of the initial Cellular V2X (C-V2X) standard, which focuses on V2X Direct Communication. Further enhancements to support additional V2X operational scenarios will follow in 3GPP Release 14, targeted for completion in March 2017. In addition, today, key auto and mobile industry players including Audi AG, BMW Group, Daimler AG, Ericsson, Huawei, Intel, Nokia and Qualcomm Incorporated, announced the formation of the global, cross-industry 5G Automotive Association (5GAA). One of the key objectives of the association is to develop, test and promote communications solutions, such as C-V2X communication and its strong evolution to 5G. The Association is creating real cross-industry momentum around the development and deployment of connected car technologies, working to support national and regional policies in Europe and globally.

The completion of the initial C-V2X specification in 3GPP represents an incredibly important milestone for the role of the cellular ecosystem in vehicular communications. C-V2X is becoming a viable modern alternative to IEEE 802.11p and the basis for significant advancements in the future as the cellular industry moves toward 5G.

George Tsirtsis, Qualcomm Technologies C-V2X Engineering Lead

In my last blog post I covered how C-V2X was introduced in 3GPP Release 14 by evolving LTE Direct and LTE Broadcast to meet the requirements for automated driving. C-V2X will serve as the foundation for the safe, connected vehicle of the future, giving vehicles the ability to communicate with each other (V2V), with pedestrians’ devices (V2P), with roadside infrastructure (V2I) and with the cellular network (V2N).

C-V2X defines two new transmission modes that together enable a broad range of use cases:

  • C-V2X Direct communications – Enhances LTE Direct device-to-device communications to enable direct exchange of real-time information between vehicles, road side infrastructure and/or pedestrians’ devices.
  • C-V2X Network communications - Leverages existing LTE infrastructure with ubiquitous coverage to bring additional services, such as finding parking or advanced accident alerts

The coexistence of the two modes of operation delivers more advanced deployment scenarios and services to vehicles, opening up new opportunities and diverse business models for operators.

In this post, I want to elaborate on why C-V2X is gaining momentum and support from key global industry players:

1) Strong ecosystem – C-V2X benefits from the fast-moving and established mobile industry

The mobile ecosystem moves quickly to meet customer expectations, while keeping backward compatibility in mind. The fast evolution and high penetration rate of mobile devices have resulted in accelerated innovation and faster adoption of new technologies. The timely completion of the initial C-V2X standard is a testament to the fast pace of innovation in the mobile industry. This uptick in pace is penetrating the automotive industry, enabling a growing set of use cases for the connected vehicles and automated driving. The collaboration between the mobile and automotive industry has been established and the 5GAA will further foster this collaboration.

2) Superior performance – Designed to operate with or without cellular network coverage

C-V2X Direct communications enhances LTE Direct device-to-device communications with innovations to exchange real-time information between vehicles traveling at high speed, in high-density traffic, and even outside of mobile network coverage areas — enabling safer driving through true direct communications on designated ITS spectrum.

Several innovations have been introduced to allow direct V2X communication in the absence of infrastructure (i.e., without cellular network coverage). For example, the standard allows scheduling resources and interference management of V2X traffic based on distributed algorithms implemented between vehicles without network assistance. Also, vehicles can use Global Navigation Satellite System (GNSS) receivers for synchronization instead of relying on cellular network coverage. When in coverage, V2X Direct Communication can be augmented by V2N’s extended range and network assistance. 

All these enhancements result in dramatic performance improvements over those enabled by IEEE 802.11p-based systems, with the ability to operate at higher relative speed up to 500 km/h and at higher node densities.

3) Strong evolution path – Continuous enhancements to accommodate new use cases

Unlike older V2X technologies, C-V2X has a technology evolution roadmap, providing a unified connectivity platform for safer vehicles of tomorrow. The C-V2X roadmap will benefit enormously from the strong LTE evolution path and the introduction of 5G technologies in the coming years, and from the mobile ecosystem as a whole. The evolution of C-V2X is already being discussed and we envision a growing set of use cases, including ultra-low latency vehicle platooning, high throughput sensor sharing, video see-through, and other automated driving requirements.

Qualcomm is driving C-V2X on the path to 5G

We are very pleased to see these positive developments. Our unique position at the intersection of the automotive and communications industries allows us to pave the road to our vision of the always-connected, more autonomous vehicle of the future by pioneering C-V2X technologies, driving a rich roadmap to 5G, and bringing new levels of on-device intelligence. We are actively driving the C-V2X work in 3GPP, which builds on our leadership in LTE Direct and LTE Broadcast to pioneer C-V2X technologies. Learn more about C-V2X here.

As a co-founder of the 5GAA Alliance, we are vey pleased about the role of the association in fostering collaboration between the automotive and communications industries. We look forward to more positive developments in this space and more collaboration between governments, as well as, telecommunication and automotive industries.