LoRa Modulation:  LoRa (Long Range) is a proprietary wireless technology that utilizes Chirp Spread Spectrum (CSS) modulation.

CSS Characteristics:

Spread spectrum technique for resilience against interference.

Chirps (frequency sweeps) enable operation below the noise floor for long range.

References

LoRa:   https://en.wikipedia.org/wiki/LoRa

Chirp Spread Spectrum (CSS):   https://en.wikipedia.org/wiki/Chirp_spread_spectrum

60GHz Absorption:  The 60GHz band experiences significant signal attenuation due to absorption by oxygen molecules in the atmosphere. This severely restricts the usable range of wireless systems operating in this frequency.

Why Other Options Don't Apply:

Atmospheric Scattering:  Impacts longer wavelength transmissions, less significant at 60GHz.

Solar Radiation:  Can cause interference on some frequencies, but not a primary range limitation at 60GHz.

Rain Fade:  Primarily affects higher frequencies (above 10GHz), but its impact is less severe than oxygen absorption at 60GHz.

References:

60GHz Propagation Characteristics:  Technical papers discussing oxygen absorption and its influence on range limitations.

Millimeter-wave (mmWave) Communication:  Overviews highlighting the challenges and short-range applications of 60GHz systems.

Health IoT Device Categories:

Wearable:  Devices worn on the body (smartwatches, fitness trackers).

Non-wearable:  Devices used without being worn (smart scales, connected medical equipment).

Implantable:  Surgically inserted devices (pacemakers, glucose monitors).

References

Health IoT:  Resources on healthcare + IoT will illustrate device types.

Privilege Creep Defined:  Gradual accumulation of excessive permissions over time, often due to users changing roles or access needs not being adjusted accordingly.

Other Terms:

Privilege Escalation: A malicious act of obtaining higher-than-authorized access.

Improper Delegation/Grouping: Faulty permission assignment, but not the gradual accretion aspect.

References:

Principle of Least Privilege:  Security best practice emphasizing the need to minimize access to only what's necessary.

Access Control Models:  Discussions of how privilege creep can violate security principles.

ITU's Mandate:  The International Telecommunication Union (ITU) is a specialized agency of the United Nations focused on global information and communication technologies (ICTs).

Radio Spectrum Regulation:  A core ITU function is allocating radio spectrum bands and satellite orbits to prevent harmful interference between different countries and technologies. This coordination is essential for the orderly use of wireless communications worldwide.

Other ITU Roles:  While involved in standard-setting and establishing best practices, options A and D are less precise than the ITU's spectrum coordination focus.

References:

ITU Website:  ( https://www.itu.int/en/ ) Outlines its activities and governance of radio spectrum.

ITU Radio Regulations:  The international treaty governing the use of the radio-frequency spectrum.

OFDM vs. OFDMA:

OFDM (Orthogonal Frequency-Division Multiplexing):  Divides a channel into multiple subcarriers for data transmission.

OFDMA (Orthogonal Frequency-Division Multiple Access):  Extends OFDM by allowing multiple users to share subcarriers simultaneously, improving efficiency and spectral utilization.

References

OFDM:   https://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexing

OFDMA:   https://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiple_access

PHP's Cross-Platform Nature:  PHP originated for server-side web development, but also has a command-line interface (CLI) enabling its use for scripts and automation tasks.

Other Options:

Some  languages are OS-specific (but less frequent with modern scripting languages) .

Many languages work in web  or  command line, not  both  like PHP.

References:

PHP (Introduction):  Overviews mentioning its dual role in server-side web applications and as a general-purpose scripting language.

PHP CLI:  Documentation on the command-line interface for PHP.

Browser Ubiquity:  JavaScript has a native runtime environment within almost every modern web browser, making it the 'built-in' scripting language for web-based interfaces.

Node-RED:  This IoT flow-based programming tool specifically uses JavaScript for its logic and automation functions.

Other Languages:

PHP: Primarily server-side for web applications

Python: Versatile language, used in some back-end IoT functions but not natively in browsers

R: Statistical and data analysis, not typically embedded in wireless solutions

References:

JavaScript (Browser Compatibility):  Documentation of its near-universal support

Node-RED (Programming Model):  Descriptions of how it uses JavaScript for node logic.

BLE Beacon Power Efficiency:  Bluetooth Low Energy (BLE) beacons are designed for low power consumption. Their primary function is to periodically broadcast short data packets (advertising their presence).

Other Technologies:

Cellular:  More power-hungry due to long-range communication and complex protocols.

GPS:  Power intensive, especially when actively tracking location.

Wi-Fi:

SSL/TLS Secures Web Traffic:  HTTPS builds upon HTTP, adding the encryption provided by Secure Sockets Layer (SSL) or its successor, Transport Layer Security (TLS).

Other Protocols Have Different Purposes:

IPSec: Secures IP traffic at a network level, can be used alongside TLS.

SNMPv3: Management protocol, offers security features, but not the primary mechanism in HTTPS.

SSH: Secure remote shell, unrelated to web data encryption.

References:

TLS (and SSL):  Explanations of their role in HTTPS and how they provide encryption for web communication.

HTTPS Overview:  Materials showing how TLS fits into the overall HTTPS architecture.