IoT Glossary

What is HSDPA?

High Speed Downlink Packet Access (HSDPA) boosted what’s possible on the 3G network.

What is HSDPA?

High Speed Downlink Packet Access (HSDPA) is sometimes referred to as 3.5G, 3G+, or Turbo 3G. When it was first rolled out in the early 2000s, it significantly enhanced the third generation (3G) cellular telecommunication system.

What is HSDPA?

The Universal Mobile Telecommunications Service (UMTS) – also known as the 3G standard – first arrived in 1999, and operators first started rolling out 3G services a couple of years later. At the time, the existing 2G protocol was fine for handling basic functions (e.g. calls, SMS and browsing). However, business users and ordinary consumers alike were starting to expect a lot more from cellular networks.

3G opened the door to higher capacity tasks: video calls being a prime example. It also opened up new possibilities for businesses exploring connected technologies for the first time, such as connecting with and tracking fleet vehicles when on the road.

HSDPA was one of several initiatives designed to improve the 3G system, so it could keep up with advancements in mobile and IoT technology.

Introduced with Release 5 of 3G in 2002, HSDPA was an improved version of the existing 3G protocol, focused on faster connection and on delivering a higher data transfer rate.

The HSDPA protocol itself is a downlink channel only: i.e. it enables transmission from a source to a connected device. However, it was later combined with a corresponding protocol, High Speed Uplink Packet Access (HSUPA). Together, these two technologies are known as HSPA (High Speed Packet Access). This represented an important evolution in 3G capabilities, enabling much more demanding mobile and IoT applications, such as streaming, and the two-way transmission of high-quality video.

The benefits of HSDPA


Compared to the standard 3G protocol, HSDPA improves the data transfer rate by a factor of at least five. Particularly relevant in real-time business applications, HSDPA delivers significantly lower latency than standard 3G. It means fewer dropped data packets and less laggy performance: highly useful in areas such as time-sensitive industrial automation.

More advanced projects

HSDPA (and HSPA in general) opened up new possibilities for delivering IoT projects using cellular networks. Examples included advanced fleet telematics and tracking services in transport and logistics, as well as real-time video surveillance.

Building on existing technology

HSDPA marked an evolution of 3G, rather than a whole new system. So, if you already had a 3G network deployed, you could potentially enhance your IoT strategy with new applications, without necessarily having to swap to a new network.

Disadvantages of HSDPA


High performance cellular networks like 3.5G (as well as 4G and 5G) are often a good choice for complex, time-sensitive, data-heavy applications; especially where users and devices are on the move. However, for other uses (e.g. asset tracking, facility management and basic performance monitoring), alternative wireless technologies such as LTE-M or NB-IoT might be a better fit.

For any project, it is important to weigh up your options to match your specific use cases with the most suitable and cost-effective technologies.


There is only so much room on the radio frequency (RF) spectrum. To make way for 5G, network operators are starting to phase out their 2G and 3G networks. In fact, in some areas, 3G networks are at more immediate risk of decommissioning than 2G ones. This is because 2G is so widely used for M2M and IoT devices and more time is needed for transitioning. In such cases, 2G will be kept going as a basic fallback for more advanced networks.

If you launch a new IoT project using 3G or 3G+, you risk having to incur extra upgrade costs in just a few years’ time. For existing applications on 3G, now is the time to think about switching, to avoid a last-minute rush later on.

Find out more

For an expert assessment of your connectivity needs and to discover the best fit M2M options for your business, speak to Wireless Logic today.

Learn more about 2G/3G Sunsetting here.

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