If you’re new to working with cellular call detail records, you may soon realize that there is no shortage of acronyms in this field and may find it difficult keep all the terms straight. Analyzing call detail records is a skill that takes time to refine and fully understand. One thing I particularly struggled with when I first started analyzing CDRs was knowing the difference between 3G and 4G terminology, how the carriers label their cell sites and more importantly, how to interpret what I was looking at in CellHawk. Here is a simplified explanation of what I learned along the way…

The first thing you’ll need to know is that each of the cellular providers’ networks have advanced over the years, with each generation of technology providing more capabilities and faster speeds of data transfers. These generations of technology are referred to as 2G, 3G, 4G and most recently, 5G. The cellular networks started off only allowing voice calls to be transmitted. As the technology improved, we started seeing the 2G and 3G networks. Then, 4G came along, which is often referred to as LTE (or long-term evolution). In recent months, the cellular providers have started releasing their newest and fastest network yet, 5G.

When 2G and 3G networks were deployed, the network configurations were divided into two categories, with each provider choosing one over the other.

In the 2G days, AT&T and T-Mobile decided to go with the network referred to as GSM or Global System for Cellular Management. When 3G was introduced, they referred to the network as UMTS or Universal Mobile Telecommunications Service. In both generations, you’ll see their cell sites referred to as a LAC and CID. LAC means Location Area Code, which is a group of cell towers. And CID stands for Cell Identification, referring to the cell number and sometimes a sector. In other words, the CID tells you where the antenna is located and which direction it faced.

Sprint, Verizon and US Cellular opted for the CDMA network or Code Division Multiple Access. This is when you see the cell sites provided in terms of switch, cell, and sector. The switch is a section of the network that controls a group cell towers. The cell refers to the “tower” or structure where the antenna is located. And the sector refers to the direction the antenna faced.

When the LTE network was introduced, all carriers began using completely different terminology to refer to their cell sites, but the good thing is that they all use the same basic terms. When mapping LTE records, you’ll see the cell sites referred to as eNodeBs and Cell IDs. The eNodeB is the Enhanced NodeB and it references a group of antennas on a cell tower. The eNodeB alone does not identify the sector. To identify the sector or direction the specific antenna faced, you’ll need to refer to the Cell ID.

Some other common terms you may see when the cellular providers refer to their cell sites are: CGI, ECGI, and ECI. Here are their definitions:

  • CGI: Cell Global Identification. This number is used in the GSM and UMTS networks and is a combination of the MCC (Mobile Country Code), MNC (Mobile Network Code), LAC (Location Area Code) and the CI (Cell Identity).
    • The Mobile Country Code identifies the country where that cell site is located.
    • The Mobile Network Code identifies which cellular company that cell site belongs to.
  • ECGI: Extended Cell Global Identification. This term is used in the LTE network for a cell tower. This number consists of the MCC, MNC, eNodeB and Cell ID.
  • ECI: An abbreviation of ECGI. It stands for Extended Cell identification.

It should be noted that upon appearance, these numbers do not look like they include any LAC/CID or eNodeB/Cell ID combinations that can be found in a cell site list. This is because these numbers have undergone a mathematical conversion and will need to be converted again to extract the specific cell site information to be looked up in the cell site list.

And lastly, there is the 5G network. This network is very new and is only available in certain cities or regions of the country. 5G is touted has being the fastest network with an increased capacity and availability to ultimately provide a seamless and improved experience on the cellular network. We have yet to see how the 5G network will affect call detail records, if there’s any difference at all.

So, there you have it… a simplified look at the different generations of cellular technology and how cellular providers label their cell sites to help you understand how to map your call detail records. The information provided is just the tip of the iceberg when it comes to fully understanding cellular analysis. If you would like to learn more, this topic is covered in much more detail in our Cellular Technology, Mapping and Analysis Course. Please visit…. for more information on the course.