What Is Dynamic Spectrum Sharing and Why Can 5G Feel Like 4G?

Dynamic Spectrum Sharing, usually shortened to DSS, lets a mobile network run 4G and 5G on the same block of spectrum. 

Instead of switching an entire frequency band from LTE to 5G overnight, the network can dynamically decide how much capacity goes to each technology. 

That’s brilliant for expanding 5G coverage. 

It’s also one reason your phone can sometimes display a shiny 5G icon while the speed feels suspiciously similar to 4G. 

The label is genuine. 

There just isn’t necessarily a massive new chunk of spectrum sitting behind it. 

“Is This 5G Actually 5G?” 

Jamie was standing outside a station comparing two speed tests. 

4G: 

72Mbps 

5G: 

78Mbps 

He stared at the screen for a moment. 

Six extra megabits. 

Not exactly the technological revolution he’d been promised. 

But his phone really was connected to 5G. 

The network was using spectrum that also had to support plenty of existing 4G customers. 

That is essentially why DSS exists. 

Ericsson describes Dynamic Spectrum Sharing as a way for networks to introduce 5G on existing LTE frequency bands without shutting down 4G on those bands. 

It’s a migration tool. 

Not a magic speed button. 

How Does DSS Actually Work? 

Think of a road carrying both 4G and 5G traffic. 

Without sharing, you might permanently dedicate certain lanes to 4G and others to 5G. 

DSS takes a more flexible approach. 

The network watches demand and allocates radio resources between 4G and 5G dynamically. 

Ericsson says its spectrum-sharing implementation can make these resource-allocation decisions in 1 millisecond intervals, depending on traffic demand, device types, radio conditions and the mix of 4G and 5G users. 

Dedicated 5G spectrum	DSS 5G
Spectrum mainly for 5G	Spectrum shared with 4G
More dedicated capacity	Capacity depends on traffic mix
Can deliver larger speed gains	May feel closer to LTE
Requires suitable spectrum	Reuses existing LTE bands
Great for capacity	Great for coverage/migration

DSS makes far more efficient use of existing assets than forcing millions of 4G phones off a frequency they still need. 

Why Doesn’t DSS Always Feel Much Faster? 

Because DSS doesn’t create more spectrum. 

It shares what’s already there. 

If a 20MHz carrier is being divided between LTE and 5G customers, your 5G phone isn’t automatically receiving a brand-new 100MHz motorway. 

There are also technical overheads involved when two radio technologies coexist within the same spectrum. 

The result can be a 5G connection that offers useful benefits without showing the spectacular download speeds people associate with dedicated mid-band 5G. 

That doesn’t mean DSS is fake 5G. 

It means 5G describes the radio technology, not a guaranteed speed. 

Then What’s the Point? 

Coverage. 

A lot of valuable low-frequency spectrum is already heavily used by LTE. 

Lower frequencies travel farther and can be particularly useful for wide-area and indoor mobile coverage. 

Completely taking those bands away from 4G customers would be impractical while millions of LTE-only devices remain active. 

Ericsson notes that DSS was important during the migration from 4G to 5G precisely because it allowed operators to reuse scarce low-band FDD spectrum for both technologies at the same time. 

So DSS helps 5G spread farther without waiting for every 4G phone in Britain to retire. 

That’s a pretty useful job. 

Even if your Speedtest screenshot looks less dramatic. 

Why Dedicated Mid-Band 5G Usually Feels Different 

Dedicated mid-band 5G can offer much more capacity. 

Instead of squeezing 5G alongside LTE users in an existing band, the network gets a larger block of spectrum built around 5G traffic. 

That is where users are more likely to see the hundreds-of-megabits results commonly associated with 5G. 

So you might experience: 

DSS 5G indoors: 60Mbps 

Then walk a few streets: 

Mid-band 5G: 350Mbps 

Same phone. 

Same network. 

Same 5G icon. 

Very different radio resources underneath. 

Don’t Judge the Network From the Icon 

This is one reason the 5G logo has confused people. 

The icon tells you that your handset has a 5G connection available. 

It does not tell you: 

• How much spectrum you’re using 
• Whether that spectrum is shared 
• How congested the mast is 
• Which 5G band you’re connected to 
• Whether you’re using 5G Standalone 
• What speed you’ll actually receive 

The icon is a clue. 

The actual experience is the answer. 

Where Talk Home Mobile Fits 

Talk Home Mobile currently provides 5G on compatible Android and iOS devices in 5G coverage areas. The network says compatible phones automatically move between 5G, 4G and other available network generations as conditions change. 

So if Talk Home Mobile shows 5G but a speed test isn’t enormously faster than 4G, don’t assume the service is broken. 

The underlying host network’s spectrum, coverage, congestion and 5G deployment type all affect the result. 

Talk Home currently advertises 5G speeds of up to 1Gbps, but as with any mobile service, actual speeds depend on network conditions. 

Sometimes 5G is about massive speed. 

Sometimes it’s about giving the network a smoother path away from 4G. 

Final Thoughts 

Dynamic Spectrum Sharing solves a very practical problem. 

Networks cannot switch 4G off overnight. 

But they also don’t want to wait years before expanding 5G. 

DSS lets both generations share the same radio spectrum while customers gradually move across. 

That can make 5G coverage expand much faster. 

It can also produce 5G speeds that look rather familiar. 

So if your phone says 5G and delivers 75Mbps, it isn’t necessarily lying. 

It might simply be sharing the road with quite a few 4G neighbours.