* Posts by bigdish

17 publicly visible posts • joined 18 Aug 2011

BT will HATE us for this one weird 5G trick


No, he's confusing MIMO with Carrier Aggregation...

HaLow, is it me you're hacking for? Wi-Fi standard for IoT emitted


Crowded house

There's plenty of other systems out there already aiming to fill this niche - LPWA (low power wide area) systems like weightless, Sigfox, CleanSlate have got a head start on HaLow and LTE-MTC is attacking from the operator end of the market - but even so, with 20 billion IoT devices (or so we're told) expected by 2025 there's more than enough of a market for all of them...

Vodafone: Can't make calls on our network? Use Wi-Fi


VoWifi not UMA

UMA was a way of bridging voice calls to the traditional circuit switched core via a UMA Controller, which pretended to be a BSC or RNC as far as the core network was concerned.

Modern VoWifi works differently by creating an IPSec tunnel from the phone, over Wifi, across the Internet to an ePDG on the edge of the operator's packet core where it gets converted to a GTP-U tunnel to connect to the GGSN or PDN-GW...and from there connects to the IMS just like a VoLTE service does.

So it's really VoLTE diverted over Wifi

Handover between cellular and Wifi can be provided by SRVCC (Single Radio Voice Call Continuity) if the ePDG supports it.

Although Vodafone might be using good old UMA and routing traffic via their CS core, I'd be amazed if they were

Ofcom: We're going to shake up the digi comms market


EE a member of UKCTA....

...so, they'll be requesting a refund of their membership fee soon then?

The Nokia ENIGMA THING and its SECRET, TERRIBLE purpose


Sorry to be boring....

...but it's going to be a 4G femtocell box that supports VoLTE and SR-VCC (and maybe LIPA & SIPTO, if they still exist) and plays nicely within a HetNet....and all that stuff...isn't it? All the rarely-used bits of 3GPP in one box!

Don't call it throttling: Ericsson 'priority' tech gives users their own slice of spectrum



...Resource Blocks occupy 180kHz of bandwidth (12 subcarriers with a spacing of 15kHz per subcarrier)...

...and normal LTE resource allocation takes place by assigning one or more RBs to each active user on a subframe by subframe basis...

...so if that's how 'normal' LTE resource allocation works I'm not sure I really understand what's new or different about the feature that Ericsson has announced? Or maybe I'm missing something...? unless what they're saying is that higher priority users are allocated RBs that have the best reported quality and that can therefore carry the highest data rates in that cell - so it's a kind of 'radio quality-based' prioritisation scheme?

SK Telecom, Ericsson trial 'elastic cell'



Isn't this just the coordinated multipoint (CoMP) idea with a sexier name?

I say 'just' CoMP, don't mean to suggest that it's not a great idea...I'd be happy to see it working but I'd be even happier to get a reliable 2G, 3G or 4G Vodafone signal here in semi-rural Bedfordshire...

Operators shackled to GSM, so Huawei ties GSM to LTE


LTE allows you to vary the bandwidth with occupied by an uplink or downlink carrier, so I guess this works by having the operator define, say, a 20MHz LTE carrier but then vary it to 15, 10 or 5MHz during periods of peak GSM demand. The GSM cell would have a fixed BCCH carrier, configured on spectrum outside of the 20MHz used by LTE, and a number of traffic-only expansion carriers, which are assigned to carriers inside the LTE allocation.

when the LTE carrier slims down the GSM carriers can be switched on, as the LTE carrier beefs up again the GSM carriers are switched off again. Neighbouring GSM sites are allocated different channels within the 15MHz freed up by LTE to avoid co or adjacent channel interference.

I can see that working...but only if the operator had 20MHz to play with in the first place...

Massive new AIRSHIP to enter commercial service at British dirigible base


Has anyone mentioned....

...Eccentrica Gallumbits yet?

She was the first thing I thought of when I saw the triple-bumped front profile of the HAV...which probably says something telling about my maturity and mental wellbeing....

Mobe operators, need to check your network? There’s an app for that


Re: They measure...

yes, and RSRQ (not RSSRQ) should be in dB too

I hope that screengrab was just a mock up....

Ofcom flogs ex-military 4G spectrum, but ONLY the iPhone 5 can use it


FD-LTE doesn't have to be deployed symmetrically - you can have asymmetrically-sized uplink and downlink channels, you can even (in theory) vary the bandwidths of the channels dynamically over time if you wanted to...TD-LTE would probably still be more flexible though with a lower 'flexibility management' overhead

also, a thought about the spectrum itself. Other posters are right to question the reach/penetration of signals at 2.3 and 3.4GHz, but I would expect this new spectrum to be snapped up for small cell use - femtos and picos - for LTE-HI type deployments, where reach and penetration are negligible concerns compared to capacity and throughput

iPhone rises, Android slips in US, UK


poking my head above the parapet...

I had iPhones for 3 or 4 years, but this time (out of a sense of perversity probably) thought I'd give Nokia a try...Nokia mark you, not Windows - that kind of comes as a side effect of buying Nokia.

I've got a Lumia 925, fantastic hardware, not plasticy, right amount of solidity and heft. Fantastic camera and Nokia smartcam software. Much better voice call quality than an iPhone.

WP8 isn't bad either - there are some features missing, it's a bit like iOS3 or 4 in the sense that it feels a bit unfinished, but I haven't much suffered from a lack of apps, most of what I actually use (as opposed to all the iOS apps I downloaded and only used once) I've got. MS need to move the Bing button though (or let us turn it off) is currently in just the wrong place for single-handed phone use, gets hit by the pad of my thumb when I'm typing one-handed.

Is the Lumia handset as good as an iPhone or Galaxy? Definitely

Is WP8 as good as iOS or Android?...maybe not yet, but WP9 might get closer.

All in all - I like it, I'll probably keep it....for a while

Mobe SIM crypto hijack threatens millions: Here's HOW IT WORKS


Re: Roaming always seemed like a bigger risk

The really secret part of the 'shared secret' - known as K - never leaves the home operator's AuC - the roaming partner is passed a set of keys that are derived from K - CK/IK for 2G/3G authentication, Kasme for 4G - but K itself is never communicated. The derived keys are refreshed during each subsequent authentication run, so knowledge of them should only provide a limited duration opportunity to a hacker.

Another 170,000 Freeview homes to be freed from reality TV - possibly


Storm in a teacup?

The EU published a roundup of interference reports and LTE test results last year taken from deployments in Germany, Sweden and the USA (who are all a bit further down the line with LTE deployment than we are in the UK) and this apparently indicated a very low level of interference and very few substantiated complaints..

http://ec.europa.eu/enterprise/sectors/electrical/files/emc/ws2012-gsma_en.pdf (PDF, short and quite readable)

... The real problems will start when people start putting their LTE femtocell boxes next to their TVs!

Sheffield ISP: You don't need a whole IPv4 address to yourself, right?


Re: "odd versions are experimental"

According to IANA, who dish out IP version numbers...

IPv5 was used for the ST Datagram mode protocol (which apparently went on to feed into the development of MPLS)

IPv6 was originally allocated to an experimental version known as SIPP (Simple Internet Protocol Plus)

IPv7 was assigned to the experimental TP/IX: The Next Internet, although the same version number was also used for a proposed version called CATNIP (Common Architecture for the Internet)

IPv8 was assigned to the experimental PIP (The P Internet Protocol)

IPv9 was assigned to the experimental TUBA (TCP/UDP with Bigger Addresses)

So, all but two version numbers have so far been experimenatl (or just skipped) and the next version of IP will have to be IPv10...probably...

Ofcom: 4G won't knock out granny's personal alarm


LTE Pedantry

Just a bit of technical pedantry ....

'Both the handset and the base station measure each other's signals and let each other know when it's OK to reduce the power' - not in LTE, only the uplink is power controlled, no downlink power control is used

'time-sliced' - sort of but not in the strictly organised way that, say, GSM is

'code-divided' - nope, not in LTE, not for user plane channels anyway.

Most of the OOB protection in this case is provided by the 'brick wall' effect of the upper guard band of null subcarriers on the upper edge of the channel, this leads to a steep dropoff in radiated power in the adjacent band. Plus the fact that the base station is unlikely to assign Resource Blocks on the edges of channels to distant phones (which would be expected to transmit the strongest uplink signals) to reduce the amount of interference caused to neighbouring cells.

Symbian Anna makes her debut


Links lead nowhere...how very Nokia...

I don't know if was just my copy - but in the Nokia press release that announced Anna (sent out this morning by Hugin) all of the hyperlinks that were supposed to point towards info on Anna actually lead to a blank page...which sort of sums Nokia and Symbian up!