Communications Criteria
Range
Frequency Bands
Power Consumption
Topology
Constrained Devices
Constrained-Node Networks
What categories of range are defined?
What factors determine the achievable range?
Environmental factors
− Landscape and field topology
− Interference
− Noise
Product characteristics
− Antenna design
− Transmit power
What are the ISM frequency bands?
These frequencies are used in many communications technologies for short-range devices (SRDs). Unlicensed means that no guarantees or protections are offered in the ISM bands for device communications. For IoT access, these are the most well-known ISM bands:
2.4 GHz band is used by IEEE 802.11b/g/n Wi-Fi, IEEE 802.15.1 Bluetooth, IEEE 802.15.4 WPAN (Wireless Personal
Area Network).
On what frequency does a microwave oven operate?
A microwave oven heats food by passing microwave radiation through it. Microwaves are a form of non-ionizing electromagnetic radiation with a frequency in the so-called microwave region (300 MHz to 300 GHz)
How can you calculate the wavelength for a given frequency?
λ = v/f
v = wave velocity (how fast the wave propagates in a medium)
λ = wavelength (distance over which a wave shape repeats)
f = wave frequency (number of waves per unit of time)
Light in air or vacuum: 299,792,458 meters per second
What are the advantages of licensed/unlicensed frequencies?
+
-
licenced
some guarantee
cost money
unlicenced
cheap
no guarantee
Give examples of access technologies using licensed/unlicensed frequencies
licensed
unlicensed
5G
WiFi
4G
Bluetooth
LoRaWan
What main topology schemes are dominant for access technologies?
Star, Mesh and Peer-to-Peer
What are the categories of constrained devices defined by the IETF?
Class 0-2
How do they differentiate from unconstrained nodes?
Name and explain these categories.
Memory, Resources how they communicate
What are constrained-node networks?
Low power Lossy Networks
They hava a high failure rate
underreact to failure
What are the network characteristics to consider?
how much data is transfered
how much power the devices have
how thw topology
costs
How do these characteristics influence your IoT network behavior?
type of device
type of communication
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