Thursday, June 16, 2016

3GPP Standards for the Internet-of-Things

3GPP described all the IoT market requirements.

1. eMTC : Enhancements to LTE for Machine Type Communications
2. NB-IoT : Which is very popular, New Radio been added to LTE
3. EC-GSM-IoT : Enhancements to EGPRS .

Here is the link to the wonderful presentation on above mentioned IoT standards.

www.3gpp.org/images/presentations/3GPP_Standards_for_IoT.pdf

Wednesday, June 15, 2016

WiFi Offloading - Part 1

Wifi Offloading :

As the name “Offload” indicates to get rid of some one or unload something from your basket. WiFi Offloading is getting popular now a days. Almost all the chip-set vendors and the operators implementing WiFi Offload support. 
The solution allows the operator to indicate how the IP flows are routed through the available access systems and to selectively offload some traffic (e.g. best effort traffic) to WLAN while using UTRAN or E-UTRAN for other traffic (e.g. traffic with specific QoS requirements). This is usually referred to as WLAN offload.

Why Wi-Fi Offload?

As you notice, the evolution of mobile communications from 1G to 4G (going forward 5G) is to accomplish new levels of user experience and multi-service capacity, especially in Data. Just recollect the days when we have Nokia and Motorola handsets operating Symbian OS. And compare now the Smart Phone era. The amount of data being used per subscriber increased drastically. No surprise that we won’t find a mobile without installing any one of the e-commerce /social networking /Banking apps. It’s not just mobiles, also Laptops, Tablets ..etc. Now it’s a challenge for the operators to think of cost effective solution to satisfy customers as the bandwidth requirements increasing day by day. This is one of the requirement opting WiFi offloading.
Answer the question, suppose you have broadband at home with WiFi enabled and mobile data enabled on your mobile. Once you reach home from office, whether you turn on WiFi or not? Of course the answer would be YES because WiFi is cheap and faster compared to Mobile Data especially indoor.
Also now a days we keep watching new devices that doesn’t support Mobile Network but WiFi and the device operator locked .
One more to say in pure technical terms “to achieve required QoS in a cost effective way”
From Carrier point of view, the investment would be very less and he always can use un-licensed spectrum and save money. From user point of view “User Experience” matters.

How WiFi offload reduce cost?

1.      For example you have an iPhone and it’s locked to one operator. Wifi is turned on and sometimes you notice instead of 4G wifi being used. Carrier can afford more subscribers and gain more income by offloading few subscribers from Mobile Data. Operators can have this kind of mechanism in universities, Railway stations or someplace where mass gathering happens. Note that the transition from mobile data to wifi should be without user intervention.
2.      This allows reducing the load on some of the network elements.
If I am not wrong user won’t get benefited much with this feature except “User Experience” J.

Disadvantages:

1.      Battery may drain quickly, since the UE keep searching for available wifi networks when the it is enabled from GUI.

2.      In my view, Offload should be Network controlled, there should be a measurement event to report the available networks and decide which is good for the UE based on the UE direction of travel and other statistics. This is not available at the moment, may add in future.

We shall look into architecture and the importance of ePDG in Part 2.

Thursday, June 9, 2016

LTE UE Category

It's a common word for the people working in telecom, for sure you hear this word once at-least a day. Identifying the UE category is very important. ue-Category defines a combined uplink and downlink capability of an UE. An UE Category usually defines the below parameters.

At Transport level :

In Case of DL :

1. Maximum number of DL-SCH transport block bits received within a TTI
2. Maximum number of bits of a DL-SCH transport block received within a TTI
3. Total number of DL-SCH soft channel bits
4. Maximum number of bits of a MCH transport block received within a TTI

In Case of UL :

1. Maximum number of bits of an UL-SCH transport block transmitted within a TTI
2. Maximum number of UL-SCH transport block bits transmitted within a TTI

At Phy Level :

In Case of DL :

1. Maximum number of supported layers for spatial multiplexing in DL

In Case of UL :

1. Support for 64QAM in UL

These are the main parameters described or defined per UE_Category. I am not going to explain or write about the above parameters in this post. Please go through 3GPP 36.306, Section 4 for more information

Below table shows the parameter values which we discussed above for DL.




Below table shows the parameter values for UL


You may not see all these parameter setting in any of the DL/UL signalling messages. Guys who are working on the T&M instruments like Anritsu or R&S can see the detailed information about the UL and DL channel setup. To be discrete, in MAC channel setup.

Ref : 3GPP 36.306

Monday, June 6, 2016

LTE CAT 1 and CAT 0

Good to hear that Gemalto showcased their VoLTE Cat.1 module capable of simultaneous voice and data at IoT world pre-event. It also has the support of #2G and #3G.

As you know for M2M, Cat1 is the preferred module


CAT1 UE theoretical throughput 10Mbps in DL and 5 Mbps in UL which is a decent throughput for operating Connecting Homes/Cars/ any IoT device.  In fact IoT doesn't require CAT1 devices too, LTE CAT 0 devices should be fair enough to handle the required throughput.

CAT 0 is a new LTE UE category developed especially for IoT requirements. Most of the IoT devices requirement is not the throughput, but long battery life. Basic throughput should be fine.

3GPP Rel 12, introduced LTE CAT 0, advantages being less complex compared to other LTE UE categories which may be around 50% less compared to LTE CAT1.



Are Verizon, AT&T, T-Mobile and Sprint building 5G networks?


Looks like US NW operators working seriously on the next generation network technology #5G. Wish #5G goes to live and boost the telecom further..


http://www.rcrwireless.com/rcrtv/verizon-att-t-mobile-sprint-building-5g-networks-carrier-wrap-episode-29-tag2