Support and operation engineers don’t need to understand the majority of algorithms hidden in telecom software. But time to time it helps if you have an understanding of how some particular functionality is implemented.
The typical situation is Traffic Shaping or Overload Protection. Many operators want to understand and test, how their system behaves under a huge load of calls or messages. There are many ways how to implement these features, so let’s take a look at the most common ones.
The easiest way how to protect the system is to define some limit. For example, we can say that our SBC is able to handle only 1.2 mil. parallel calls. If we receive a new invitate which exceeds this threshold, we respond with system error.
Similarly, we can set a limit for CPU or memory consumption. Whenever we reach, let’s say 60 % of the CPU we raise an alarm and don’t allow any new call/registration. As soon as the resource utilization drops below the threshold again, we can resume the standard system behavior and accept new calls.
Sounds reasonable and simple, however, in case that the load is close to our limit – 60 % of CPU – it can lead to so called throttling causing system instability. The last thing which you desire for if you are facing high traffic.
After years in mobile industry with 5G I’ve recently started to be more cautious about health implications. For last 12 months I’m going through various studies and honestly it is difficult to come to any final conclusion. Some researchers claim that there is no evidence cell phones would increase risk of cancer, some argument with studies on rats, where radiation makes rats uniquely prone to a rare tumor called a schwannoma. As a technician it is hard to judge for me, but there are some basic facts, which I’ve noted down:
to call only is not that bad, to use mobile for data is a completely different story
non-ioinizing radiation maybe more harmful than it was thought
studies reveal that the exposure to cell phones, laptops, or Wi-Fi affect sperm in their count, morphology, motility, an increased DNA damage
we don’t have much evidence on mobile induced cancer when it comes to humans
studies are mostly miles behind the current technological development
distance matters – just a few centimeters can make a difference
What would happen if the scientists would actually prove, that 5G can mean a serious risk to us? Many people are so adicted to Internet, that they are ok to pay by their own health anyway. Not talking about all those companies which invested so much into 5G and AR/VR.. Lets’ wait for some clear data and don’t keep cellphones in our pockets till then – just for sure.
GSMA Intelligence forecasts that the number of 5G connections globally will reach 1.3 billion by 2025, covering 40 percent of the world’s population or approximately 2.7 billion people. At that time, the Americas region is expected to account for over 260 million 5G connections or 20 percent of the global market.
The question everyone is asking in telco last couple of years is – do we really need 5G? Do we really need that throughput for our voice, video and messaging services? Can we significantly improve real-time communication services so that customers would be willing to pay for it? RCS aka Advanced Messaging is a great example of how difficult it can be to find the right business model for new technologies. EVS supported in 4G is more than what we need for voice calling. Although video calling is possible in 4G, not that many customers are using this option on their mobile devices. More popular than video is desktop-sharing, collaboration and communication in context. Well, lower latency and better throughput can be useful – but is it a reason strong enough to invest into the new 5G infrastructure, when collaboration applies mainly to fixed networks?
5G Drivers. Source GSMA
Still there are real-time communication applications which require low latency and huge amount of data so that 4G is not enough. Virtual Reality (VR) applications like 360-degree video will necessitate higher resolutions of 8K and above, and stereoscopic video (which separates left and right eye views in VR) also requires additional bandwidth. When most people hear about 3D video, holograms, Augmented Reality (AR) and Virtual Reality (VR), they mostly think about gaming. And yes, gaming can be a good example and people like to spend money for entertainment. But there are other examples, where AR and VR can make a difference.
Impossible not to mention. Ethereal – these days known as Wireshark – is twenty! In 1998 Gerald Combs publicly released its first version 0.2.0. And he truly changed the IT (and particulary telco) world. Over the years Wireshark has won several industry awards,and it is one of the top-rated sniffers. Wireshark is a real gift for every engineer who works with a protocol stack. At the same time many BIG companies don’t even realize what contribution Wireshark means to their daily business!
Thank you Gerald and everyone who has helped with this great project!
So we have a first robot citizen. When we read about human-robots they are presented as future cleaning-ladies, news anchors, soldiers or sex-machines.
Everyone can imagine possible threats. In the current world of spam and fake news robots can manipulate our reality even in a more advanced way. It’s not just a robot shop assistant which – by the way – mentions how great is a new laundry detergent or your joy-robot asking for an upgrade in a (im)proper time. It can also spy what you have at home, how much time you spend with various activities, assess your income or overhear conversation with your spouse – all, of course, in your best interest (let’s call it cookies 2.0). Not talking about real malware and ransomware.
In the same way participants in reality show forget about TV cameras, we’ll forget that robots are just robots. They don’t even need to look very real. Our brain is not that difficult to deceive. So the question is how to protect ourselves. At some point AI outsmarts human brain and we’ll need some help.
Let us know in comments section, what is your view and how to protect ourselves – e.g. how a new antispam sw/hw could look like.
Everyone knows that SIP headers like R-URI, To, From, P-Asserted-Identity, Path, Route and others contain Uniform Resource Identifiers (URI) – sip uri or tel uri. But do you know what formats we can use, with what parameters? As URI is one of the IP communication’s corner stones, it worth to have some better understanding.
SIP URI in VoLTE
Let’s start from the beginning. SIP URI is defined in RFC 3261, TEL URI in RFC 3966 (this RFC defines also modem and fax URL schemes).
SIP URI has a similar form to an email address. It contains typically a username and a hostname, for example email@example.com, where realtimecommunication.info is the domain of a SIP service provider. TEL URI is simply a telephone (landline or mobile) number as tel:+611234567890. It is needed mainly to support CS related scenarios and Mobile Number Portability (MNP). In practice we can see various forms of sip-uris:
Last but not least we have also a SIPS URI, which specifies that the resource is to be contacted securely. For that we use TLS as a transport layer protocol. The format for a SIPS URI is the same, except that the scheme is “sips” instead of sip. Note, that any resource described by a SIP URI can be “upgraded” to a SIPS URI by just changing the scheme, if it is desired to communicate with that resource securely.
Maybe you remember what I said about Group Messaging. That all the RCS deployments would be done faster without this feature. A similar thing we can say about VoLTE Conferencing. Ad-Hoc Multi Party Conference Call (CONF) is one of the basic requirements we have on VoLTE calling. Simply put each VoLTE network has to support conference calling. But to troubleshoot this great functionality can be a nightmare.
Ad-Hoc Multi Party Conference is one of the Supplementary Services supported by Telephony Application Server (TAS) (a dedicated Conference AS is an option too) and it is described in GSMA IR.92, which then refers to 3GPP TS 24.605 and 24.147. Today we’ll take a look at the conference call flow, along with the Mr’ interface between TAS and Media Resource Function (MRF).
Add participant button
Although we talk about conferencing, in fact it’s just a multi-party call. We don’t schedule any conference call for a given list of participants. We can only add additional numbers to an existing call. That’s why we describe the service as an ad-hoc conference. From the mobile operator point of view the conferencing service provides the means for a user to create, manage, terminate, join and leave conferences as well as the ability to update the involved parties. But most of the stuff is truly hidden to the end subscribers.
In general both voice and video conference can be supported, but only the support of audio media is required by VoLTE standard. The maximum number of participants differs network to network, usually it is between 6 and 10. Note, that the functionality is not limited to VoLTE users only, we can add to the call the CS users too.
Our current economy is digitized and generates an exponential growth of person-to-person (P2P) transactions. On the other hand we often face challenges around flexibility, trust, identity and authorization that existing financial instruments are sometimes struggling to address.
And that’s where blockchain comes into play. Blockchain is designed as a secure distributed system with high Byzantine fault tolerance. The most successful use cases for blockchain today are related to financial transactions and the management of financial assets. The most famous examples include Bitcoin, Ethereum, Ripple or Hyperledger.
GSMA has just recently published the final numbers for 2017. As expected the last year we’ve seen less 4G deployments than in 2016.
4G Deployments in 2017
The only exception was the RCS. (Btw. GSMA released its Universal Profile Version 2.0 for Advanced RCS Messaging.)
From the population coverage point of view the last year meant a great step forward. Although many developing countries have been still more focused on 3G (4G coverage is on average 35% there), the overall number of 4G coverage increased significantly.
It’s very interesting (and well, a bit suspicious) that the main focus of most VoLTE textbooks and trainings is signalling. But from the user-point-of-view, it is the voice data, what matters. As an end-subscriber I don’t care about signalling. My only interest is the call quality. But times they are a changin and engineers are asking about how to improve the overall voice-call quality and user experience. Today we’ll go through the basics as jitter, mouth-to-ear delay, packet loss rate or MOS, needed for QoS analysis.
For real-time multimedia we used to have dedicated telephone/radio networks. That has changed and voice/video streams are transported over IPnetwork now.
We should understand that these IP networks were originally designed for data transport. To transport data we prefer the best-effort service model, which allows an easy network scaling and simple routers’ logic. On the other hand we don’t care much if packets arrive in-order or what are the delays between particular packets. We simply wait until we receive a whole file. If any packet is lost, TCP will re-transmit it.
Packets in Data Networks
It’s a different story with the real-time communication services though. RTC applications are less sensitive to packet loss, but they are very sensitive to packet delay. Usage of IP data network as a carrier brings a lot of challenges which have to be addressed by media protocols and network elements.