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Nervous System: Before the Battle Over 5G, There Was the Battle Over 3G

David Kalat

November 9, 2020

David Kalat writes about the 5G cellular landscape and the history of innovation, competition, debate, and patent wars involved in cellular telephone technology and service.

When cellular telephone technology was first introduced, it was a luxury product for a select few. This was in part because the technology could support only a small number of users, who bore the brunt of paying for the entire infrastructure. Making cellular service available to the masses meant finding a way to drastically increase the number of concurrent users. Solutions to this problem tended to revolve around patents held by a single company, Qualcomm. Companies that wanted to avoid paying royalties to Qualcomm would need to engineer alternative technologies. This would lead to a format war, a battle over international standards, and a highly ironic conclusion.

The cellular era began on April 3, 1973, when a Motorola engineer named Martin Cooper made a historic telephone call from the streets of New York. Although not as well known as Alexander Graham Bell’s legendary first telephone call to Thomas Watson in 1876, Cooper’s call is in many ways as historically significant. Cooper was walking between 53rd Street and 54th Street when he placed the call from a handheld wireless phone.

Early cellular service was cumbersome and expensive. Because the technology treated calls like radio broadcasts, they were easy to eavesdrop on. Additionally, the expensive overhead costs for cellular infrastructure could support a very limited number of concurrent users. Before cellular service could take off as a commercial offering, problems like these would need to be overcome.

Switching from analog radio to digital transmissions in the 1980s created an opportunity for a clever technical trick that could increase the number of subscribers exponentially, while preserving their security and providing superior service. The gimmick depended on the fact that cellular phone users are not constantly broadcasting or receiving data—even the most motor-mouthed speaker needs to take a breath once in a while, and users checking their emails or browsing webpages need only short bursts of data transmissions at a time. Instead of allocating a particular channel to a single user, the same channel could accommodate multiple users at once, if they took turns. Having access to a cellular connection does not mean uninterrupted exclusive use of that connection. It will be shared.

Exactly how to share that connection, however, has been the source of endless innovation, competition, debate, and patent wars. The variety of approaches tried by competing carriers gave rise to a patchwork of incompatible technologies.

One approach to sharing a cellular connection was to divide the access by timeslots. Time-division multiple access (TDMA) was the backbone of the second generation of cellular technology, colloquially called 2G and also known as the Global System for Mobile Communications (GSM). GSM’s time-division splitting had many advantages and allowed subscribers to move easily between networks and switch carriers. Ultimately, GSM would become the most widely adopted cellular standard, serving over five billion customers worldwide. However, time-sharing cell service, like a vacation time share, was not especially efficient. A user’s time slot came up at regular intervals, regardless of that user’s actual need.

A competing technology emerged with the third generation of cellular technology, 3G. Code-division multiple access (CDMA) allowed all users on a network to broadcast simultaneously by breaking the transmissions into pieces identified by a binary code number. The phone company’s base stations could use the code numbers to reconstitute the original constituent streams.

CDMA could aggregate a much denser network of users within the same radio bandwidth, but it was an engineering challenge. As it happened, many of those engineering challenges were solved by technologies developed and patented by Qualcomm.

For example, the system requires the various signals to share the same underlying strength. This means that the movement of the cellular subscribers through space is a form of noise that needs to be filtered out. As a solution, cellphones made in the US were fitted with Global Positioning System (GPS) chips to leverage the existing infrastructure of GPS satellites to calculate the necessary adjustments.

In Europe especially, there was resistance to accepting a standard built around US-owned GPS satellites and a US-based company’s patents. Consequently, Europeans invested in their own GPS system called Galileo, launched in 2005, which would be used by an alternate version of CDMA technology designed to prioritize reusing as much of the GSM infrastructure as possible.

The result was a fractured marketplace of incompatible standards. The United States largely adopted 3G CDMA technology, while most of the rest of the world continued to rely on GSM. Even different carriers within the US, such as AT&T and Verizon, adhered to separate standards. A phone purchased from one carrier could not be used on a rival carrier’s network.

After decades of failing to establish a universal cellular standard, the fourth generation of mobile cellular emerged. Long-Term Evolution (LTE) offered backward compatibility with the competing 2G and 3G technologies. This allowed for smooth handoffs across networks and international cross-compatibility. For many carriers and manufacturers, the strongest appeal of the LTE standard was that it had so little to do with Qualcomm’s patent library.

As LTE became increasingly adopted, though, Qualcomm purchased critical LTE-related patents through acquisitions. The extensive research and development that European companies had invested in to evade being beholden to Qualcomm simply ended at the same destination anyway.

Qualcomm is currently competing for its place in the 5G cellular landscape. Because the standard is still being developed and deployed, the final understanding of the underlying patented technologies remains unknown. Qualcomm and Intel are the two US companies with the largest known 5G patent portfolios, but the Chinese company Huawei has the largest known 5G patent library overall. As carriers and handset manufacturers commit to certain design standards oriented around one version of 5G or another, differing manifestations of a 5G standard are coming into place without the unifying standardization of 4G LTE. The current battle over 5G is likely to return the cellular market to the conditions before LTE, when incompatible competing standards took root in different markets.

 

The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions, position, or policy of Berkeley Research Group, LLC or its other employees and affiliates.

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David Kalat

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