CWNP CWISA-102 - Certified Wireless IoT Solutions Administrator

WWAN (Wide-Area Wireless Network): WWANs provide connectivity over extensive geographic areas, typically covering regions or even entire countries.

Cellular Technology: WWANs often rely on cellular networks (3G, 4G, 5G) offered by mobile carriers.

References

WWAN: https://en.wikipedia.org/wiki/Wireless_wide_area_network

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

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.

Capacity Planning: The number of devices a wireless network can support is the primary determinant of its required capacity. This is because:

Traffic Load: Each device generates network traffic that contributes to the overall load.

Resource Sharing: Devices compete for airtime and bandwidth resources.

Device Type: Requirements vary; a simple sensor has different needs than a video camera.

IETF's Focus: The Internet Engineering Task Force (IETF) primarily develops and standardizes internet protocols operating at the Network Layer (Layer 3) and above in the OSI model.

Key Protocols: Some prominent IETF-developed protocols include:

IP (Internet Protocol): Foundation of internet addressing and routing.

TCP (Transmission Control Protocol): Reliable, connection-oriented data transport.

UDP (User Datagram Protocol): Connectionless, best-effort data transport.

DNS (Domain Name System): Translates domain names into IP addresses.

HTTP (Hypertext Transfer Protocol): Web communication.

References

IETF Website: https://www.ietf.org/

OSI Model: https://en.wikipedia.org/wiki/OSI_model

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.

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

SINR vs. SNR:

SNR (Signal-to-Noise Ratio): Measures the power of the desired signal relative to background noise.

SINR (Signal-to-Interference-plus-Noise Ratio): Considers both background noise and interference from other signals operating on the same frequency.

Practical Importance: SINR is a more realistic indicator of real-world signal quality in wireless environments where interference is a significant factor.

References

SINR: https://en.wikipedia.org/wiki/Signal-to-interference-plus-noise_ratio

SNR: https://en.wikipedia.org/wiki/Signal-to-noise_ratio

LoRa: Refers to the physical layer chirp spread spectrum (CSS) modulation, enabling long-range, low-power communication.

LoRaWAN: An open MAC layer protocol that builds on LoRa, defining network architecture, device management, and data routing for large-scale LoRa networks.