4G stands for 4th
Generation wireless standard. International Telecommunications Union (ITU) is a
body responsible for standardization. When a wireless standard is defined e.g.
2G, 3G or 4G, ITU puts forth a particular set of requirements. By definition,
4G network requires a mobile device to be able to exchange data at 100Mbits/sec
(downlink) and 50Mbps (uplink) using a 20MHz wide channel. 4G networks offer
speeds 10 to 12 times faster than previous 3G networks.
Everything you do with your
mobile i.e. calling your friend, posting on facebook, taking a photo and
uploading it on google cloud, you streaming Netflix on your mobile phone is
governed by set of rules, known as protocols. 3GPP (3rd Generation
Partnership Project) is a body that defines the rules or protocols so that one
element in the network talks to other element. Why is this important? Because
otherwise, you cannot take your phone and use it in some other country on your
vacation.
What we hear today is the term
LTE which is often interchangeably used for 4G or in conjunction as 4G LTE. LTE stands for Long Term Evolution and is not
a standard but a path used to achieve 4G speeds and connection rates. Today
Verizon covers the entire nation with its best in class 4G LTE network. The
figure below shows the building blocks of a basic 4G LTE Network (From Access
to Core)
As you can see from the figure above, for a regular user,
he/she just makes a call or browses the internet on the mobile phone, sends a
whatsapp msg but in practice that single action traverses and touches upon many
different elements of a carrier’s network.
Access Network: The UE and the eNB together form an access
network. Core Network: Also termed as Evolved Packet Core (EPC)
comprises of all the other network elements.
The main building
blocks of 4G LTE network are as follows:
-
User Equipment (UE): it is your mobile or any
device (tablet, PC, smartphone) that connects to 4G LTE network
-
eNodeB (eNB): In simple terms, these are the
radio towers. Your mobile is connected to the network via these towers.
-
MME: Stands for Mobile Management Entity. It is
the brain of the core network. It is responsible for mobility management,
paging and authentication of the mobile device.
-
Serving Gateway (SGW): It is the interface in
between eNB and Core Network. Put is simply, it acts as a router for the mobile
device.
-
Packet Gateway (PGW): It serves as a gateway to
the external network (e.g. Internet). The external network is termed as Packet
Data Network (PDN). A PGW connects to multiple PDNs.
-
Policy and Charging Rules Function (PCRF): It
ensures only the authorized users get the desired level of service.
-
Home Subscriber Server (HSS): It is the main
database in EPC. Stores all subscriber information.
No comments:
Post a Comment