In mobile communications, there are a little too many technologies and terminologies. Even though their purpose is to consistently enhance and evolve the mobile networks, they can also sometimes lead to confusion. If you are reading this article then you are probably already familiar with the terms HSPA and LTE. These terminologies represent two very different cellular technologies that are not at all the same. But there is a relationship between HSPA and LTE which we will explain in this post.
HSPA (High-Speed Packet Access) is a 3G UMTS network enhancement that offers peak download speeds of up to 14.4 Mbps with an average speed of around 5 Mbps; LTE (Long Term Evolution) is a 4G technology that offers peak download speeds of up to 300 Mbps with an average speed of around 15-20 Mbps.
Even though LTE is the primary technology that allows mobile operators to migrate from 3G to 4G, it is not the only upgrade path. There is another technology called WiMax (Worldwide Interoperability for Microwave Access) that can also enable 4G. However, LTE has been the most widely deployed technology that has allowed mobile operators around the world to migrate their 3G UMTS and CDMA2000 networks to 4G. As a result, LTE can also be seen as a step towards streamlining the mobile network evolution. LTE uses the network resources more efficiently, reduces the latency in data transfer, and also simplifies the overall network architecture.
HSPA, on the other hand, is a third-generation standard (3G). It is a combination of two inter-related technologies HSDPA (High-Speed Downlink Packet Access) and HSUPA (High-Speed Uplink Packet Access). HSDPA enhances the downlink speeds of the UMTS networks to help with the downloads. It adds new capabilities to the UMTS networks by introducing a new high-speed downlink channel. This channel is shared among multiple users. HSUPA addresses the upload speeds by creating a high-speed uplink channel between the mobile phone and the base station.
Data speeds for HSPA and LTE
Since HSPA and LTE represent two different generations of mobile networks, the speeds they offer are different also. The download side of HSPA is enabled by HSDPA which can offer peak downlink speeds of up to 14.4 Mbps. HSUPA is the other half that takes care of upload speeds and allows peak speeds of up to 5.76 Mbps. HSPA is also often referred to as 3.5G and is shown on a mobile phone screen as ‘H’ or ‘3G+’. It later saw a further enhancement in the form of HSPA+ which stands for Evolved High-Speed Packet Access. HSPA+ is a technology upgrade to HSPA which maximises the data speeds achievable through 3G UMTS networks. HSPA+ can offer peak data speeds of up to 42 Mbps in the downlink for downloads and 11.5 Mbps in the uplink for uploads.
The achievable speeds from the LTE networks depend on the deployment techniques. LTE can use different combinations of modulation techniques and channel bandwidth. When a 20 MHz channel is used with 64 QAM (Quadrature amplitude modulation), the LTE network can offer peak speeds of up to 300 Mbps in the downlink and 75 Mbps in the uplink. The uplink helps with the uploads and the downlink helps with the downloads. With the newer variants of LTE, LTE Advanced and LTE Advanced Pro, the downlink speeds can move up to 1Gbps and 3Gbps respectively. LTE Advanced can be seen on mobile phones as LTE+ or 4G+.
The above speeds or data rates are peak speeds that represent the maximum achievable speeds in ideal network conditions. Factors like the distance between the user and the base station, the number of users being served simultaneously by the base station, and any obstructions e.g. tall buildings can impact the average 4G LTE speeds. In busy hours, the network speeds often get a bit slower even if you are getting a full signal. To sum up, the peak-speeds for LTE, LTE Advanced and LTE Advanced Pro are as follows:
- LTE – up to 300 Mbps in the downlink
- LTE-Advanced – up to 1Gbps in the downlink
- LTE-Advanced pro – up to 3 Gbps in the downlink
While LTE speeds are good enough for most of the things we do in our day-to-day lives, the fifth generation of mobile networks (5G) takes things to a whole new level. 5G uses a different technology called New Radio (NR) which you can learn more about in this post. Mobile networks are backwards compatible which means that a 5G NR network can still also access both 4G LTE and 3G UMTS.
Here are some helpful downloads
Thank you for reading this post, I hope it helped you in developing a better understanding of cellular networks. Sometimes, we need some extra support, especially when preparing for a new job, studying a new topic, or maybe just buying a new phone. Whatever you are trying to do, here are some downloads that can help you:
Students & fresh graduates: If you are just starting, the complexity of the cellular industry can be a bit overwhelming. But don’t worry, I have created this FREE ebook so you can familiarise yourself with the basics like 3G, 4G etc. As a next step, check out the latest edition of the same ebook with more details on 4G & 5G networks with diagrams. You can then read Mobile Networks Made Easy, which explains the network nodes, e.g., BTS, MSC, GGSN etc.
Professionals: If you are an experienced professional but new to mobile communications, it may seem hard to compete with someone who has a decade of experience in the cellular industry. But not everyone who works in this industry is always up to date on the bigger picture and the challenges considering how quickly the industry evolves. The bigger picture comes from experience, which is why I’ve carefully put together a few slides to get you started in no time. So if you work in sales, marketing, product, project or any other area of business where you need a high-level view, Introduction to Mobile Communications can give you a quick start. Also, here are some templates to help you prepare your own slides on the product overview and product roadmap.