Embedded Systems Communication | CompTIA Security+ SY0-601 | 2.6c

In this video you will learn about embedded systems communication such as: 5G, narrowband, baseband radio, SIM cards, & Zigbee.


5G is the fifth-generation technology standard for broadband cellular networks, which cellular phone companies began deploying worldwide in 2019, and is the planned successor to the 4G networks which provide connectivity to most current cell phones.  5G networks are predicted to have more than 1.7 billion subscribers worldwide by 2025.[1]  Like its predecessors, 5G networks are cellular networks, in which the service area is divided into small geographical areas called cells.  All 5G wireless devices in a cell are connected to the Internet & telephone network by radio waves through a local antenna in the cell.  The new networks have higher download speeds, eventually up to 10 gigabits per second.[2]  In addition to 5G being faster than existing networks, 5G has higher bandwidth & can thus connect more different devices, improving the quality of Internet services in crowded areas.[3]  Due to the increased bandwidth, it is expected the networks will increasingly be used as general ISPs for laptops and desktop computers, competing with existing ISPs such as cable Internet, and also will make possible new applications in IoT and machine-to-machine areas. 

Some of the key advantages of the 5G network are the following:[4]

  • Expanded communication capabilities, thus increasing the capacity to connect more people and devices.
  • A lower latency of 1ms, which will enable users to encounter fewer lags & delays when attempting to access data through the network.
  • Higher rates of data, which can range between 1 & 10 Gbps, thus enabling users to download and game quickly.


Narrowband signals are signals that occupy a narrow range of frequencies or that have a small fractional bandwidth.[5]  In the audio spectrum, narrowband sounds are sounds that occupy a narrow range of frequencies.  In telephony, narrowband is usually considered to cover frequencies 300-3400Hz, i.e. the voiceband.  Another component of narrowband is called Narrowband-IoT (NB-IoT).  NB-IoT standards are based on low-power wide-area technology developed to enable a wide range of new IoT devices & services.  NB-IoT significantly improves the power consumption of user devices, system capacity, & spectrum efficiency, especially in deep coverage.  NB-IoT low-power consumption extends battery life to more than 10 years, which can be supported for a wide range of use cases.  NB-IoT is also supported by all major mobile carriers, along with chipset and module manufacturers which can coexist with 2G, 3G, 4G, & 5G mobile networks.  It also benefits from all the identity confidentiality, entity authentication, data integrity, & mobile equipment identification.[4]

Baseband Radio

Baseband radio refers to a signal at a very narrow frequency range on which data or information is superimposed & then transmitted.  It is also called a lowpass signal since it can include near-zero frequencies.  In this sense, a sound waveform is considered a baseband while radio signals often rated in the megahertz levels are not considered baseband.[6] 

Telecommunication networks, as we now know them, consist of 4 distinct parts:[4]

  • A radio access network (RAN)
  • A core network
  • A transport network
  • An interconnect network

These networks carry 3 distinct traffic types, commonly referred to as planes.  The control plane carries the signaling traffic, the user plane carries the user data, which is the content of communications, & the management plane carries the administrative traffic.  The administrative traffic contains configuration & control commands for the RAN & core functions.  Network security is critical to these planes because all 3 of them are prone to unique and diverse types of threats.  There are serious issues in pre-5G baseband, including the ability to remotely turn on a microphone and listen in, send all calls to voicemail, remotely execute code, & crash the device.  It’s now trivial to set up a fake base station & have phones connect to exploits.  Users should ensure they only load known signed/good applications, that their phones have the SIM chip encrypted/password protected, that they allow updates to the OS, and that they immediately report any issues to their providers.[4]

Subscriber Identity Module (SIM) Cards

A SIM card is an integrated circuit (IC) intended to securely store the international mobile subscriber identity (IMSI) number & its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones & computers).  A SIM contains a unique serial number, international mobile subscriber identity number, security authentication & ciphering information, temporary information related to the local network, a list of the services the user has access to, and 2 passwords:  a PIN for ordinary use and a personal unblocking key (PUK) for PIN unlocking.  There has been an increase in SIM jacking/swapping which is when someone convinces an employee of a telecommunications company to move a legitimate user’s IMSI number to a new SIM card for the attacker, and the attacker then uses this access to reset passwords and perform account takeovers.[4]


Zigbee is an IEEE 802.15.4-based specification for a suite of high-level communication protocols used to create personal area networks (PANs) with small, low-power digital radios, such as for home automation, medical device data collection, & other low-power low-bandwidth needs, designed for small scale projects which need wireless connection.  The technology defined by the Zigbee specification is intended to be simpler & less expensive than other wireless PANs (WPANs), such as Bluetooth or more general wireless networking such as WiFi.  Applications include wireless light switches, home energy monitors, traffic management systems, & other consumer and industrial equipment that requires short-range low-rate wireless data transfer.  Its low power consumption limits transmission distances to 10-100 meters line-of-sight, depending on power output & environmental characteristics.  Zigbee devices can transmit data over long distances by passing data through a mesh network of intermediate devices to reach more distant ones.  Zigbee is typically used in low data rate applications that require long battery life and secure networking.  Zigbee networks are secured by 128 bit symmetric encryption keys and Zigbee has a defined rate of 250 kbit/s, making it best suited for intermittent data transmissions from a sensor or input device.


  1. Positive 5G Outlook Post COVID-19: What Does It Mean for Avid Gamers? Forest Interactive. 29 June 2020.
  2. Edwards, B. & Hoffman, C. (2022, Apr 25). What Is 5G, and How Fast Is It? How-To Geek.
  3. 5G Explained: What It Is, Who has 5G, and How Much Faster is It Really? CNN. 2021, Nov 27.
  4. Santos, O.; Taylor, R.; Mlodziannowski, J. CompTIA Security+ SY0-601 Cert Guide.
  5. Hagen, J. (2009). Radio-Frequency Electronics: Circuits and Applications.
  6. Baseband. Techopedia.