When you read the specs LTE, now being simply called ‘4G’ (incorrectly) by the mobile providers, is the mobile network answer to “Life the Universe and Everything”. With its super high speeds and very low (10ms) Latency it certainly has the credentials to change the world. But, we’ve been there before with 3G and that didn’t deliver what was promised. Call me a sceptic but I can see that happening all over again!
Let’s take a look at what happened with 3G. The first 3G standard called ‘UMTS’ promised us 384Kbps. Not exactly broadband, but so much better than GPRS that we all thought ‘that’s it!’, finally a mobile data standard that could allow data rich applications to work reasonably well. But, that wasn’t the case. There were three real problems:
- We didn’t get 384Kbps to ourselves, but rather had to share bandwidth with all the other users connecting to that mobile antenna
- The 384Kbps came with huge amounts of latency
- We often didn’t get a 3G service anyway as our mobile devices ‘down-levelled’ to GPRS (2G) due to the lack of a 3G signal
- In service provider speak there was insufficient capacity in the ‘mobile backhaul’. In other words the wired circuits (and other infrastructure) coming away from the mobile antenna could not accommodate lots of users all working at 384Kbps at the same time. After all if you only plumbed in an E1 link (2Mbps) to the mobile tower and 10 users, for example, all tried to use their 384Kbps at the same time they need 3.84Mbps which you haven’t got and so they compete and suffer congestion.
- Latency was partly caused by the overloading of the link as in 1 above (latency of congestion) and partly by poor wireless signal forcing re-transmission of the data. By the way, at this time no regular ‘end user’ had ever even heard of latency and would have had no idea how much this would slow down their communications - but more users are aware of latency now
- The mobile providers were simply not prepared/able to invest enough in their networks to have sufficient 3G coverage.
So what’s changed? while technically speaking the LTE standards offer very high speeds and low latencies, in my opinion there is an enormous potential to repeat the errors of the past. i.e. not provision sufficient back-haul, and simply having insufficient 4G coverage causing mobile devices to fail down to 3G, or worse GPRS.
And why is that likely to happen, well, I just can’t see why the auction process for the 4G licenses will go any differently from the 3G, and there’s much less money around today too. So, without the cash to build the expensive LTE infrastructure, with its high-speed, low latency design, real world speeds and latencies will be dominated by exactly the same 3 pitfalls above that made the dream of 3G turn into the damp squib of reality. Think that won’t happen? Notice how slow your home-broadband can get at times..
Posted by Frank Puranik
Frank is Product Director at iTrinegy. With more than 30 years in the computing industry. He is an expert in the performance issues of applications across the world’s most complex networks.