Deconstructing LTE/4G Testing
by Kyle FlahertyTechnology, particularly when it is emerging, is often lumped together using shorthand terms that take on a life of their own. Two great examples that we have been discussing lately are "cloud computing" and "LTE/4G." The former lumps together several different technologies including virtualized data centers, hypervisors, and more. Meanwhile, the term LTE/4G has dozens of different components, all of which are critical and all of which often must be tested individually AND as a part of the system.
Today we are going to separate and examine the different parts that make up LTE/4G, and preview a webcast that shows you -- no matter which portion of an LTE (Long Term Evolution) architecture you own -- how to simulate and test each of them. I'm going to start by looking at the entire LTE setup, then each of the parts, and then the protocols necessary to make it work.
LTE Architecture
One of our first posts on LTE/4G discussed several of these individual parts, and we have also created a graphic to help visualize an LTE implementation:
Starting at the far left, you see the individual mobile device, otherwise known as User Equipment or UE. A UE connects over radio frequency (RF) to a tower that transmits on the LTE spectrum. One of the most significant parts of LTE, and really where the "Evolution" in "Long Term Evolution" comes in, is the eNodeB. Think of an eNodeB as comprising the communications architecture that makes LTE possible, including communications between the tower, the SGW (Serving Gateway), and the MME (Mobility Management Entity), which is the main signaling node that deals with registration and a lot more.
The diagram above shows you how, in LTE, the UE is connected to eNodeB, then eNodeB is connected to MME, and so on. The PDN on the right is the Packet Data Network, commonly known as the Internet. (Kris Raney offered a humorous but highly informative tour of telecommunications acronyms in "A Visitor's Guide to Telecom-Land.")
Each of these parts, subsystems, and the system as a whole must be tested. This is what I discussed with our product development director Scott Register the other day during the webcast "Testing LTE Infrastructure Easily and Economically at Massive Scale." During our conversation, Scott shows how BreakingPoint simulates different segments of this infrastructure in order to test exactly what you need.
Below, I've included a three-minute excerpt from the webcast that details the LTE architecture and gives an overview of the key LTE/4G protocols, GTP, S1AP, and SCTP:
In the full webcast (watch here) we discuss how to test each element and emulate each protocol, as well as give a step-by-step look at the BreakingPoint LTE Test Lab. Furthermore, Scott also dives into 3G testing, which remains a critical need for service providers and equipment manufacturers.
The LTE testing webcast is now available for download. No matter which part of the LTE/4G infrastructure you're responsible for, this webcast will help you learn how to create live mobile interactions to test LTE before deployment.
