bez diskuze a zaveru

1 files changed, 13 insertions, 33 deletions

diff --git a/text/protokolyLPWAN.tex b/text/protokolyLPWAN.tex
index 5cf2cea..19f1770 100644
--- a/text/protokolyLPWAN.tex
+++ b/text/protokolyLPWAN.tex
@@ -60,7 +60,6 @@ However, due to the advancement of technology, and the need for frequency space,
 
 The deployment of \ac{LoRaWAN} or LoRaWAN-like networks necessitates the implementation of dedicated gateway infrastructure, a characteristic that, conversely, affords enhanced control over network coverage compared to cellular technologies such as 4G and 5G which is dependent on mobile operators.
 
-% https://www.semtech.com/lora/what-is-lora
 
 \subsection{Wi-Fi}
 
@@ -73,32 +72,22 @@ Other key advantage of Wi-Fi is its ubiquity. This makes it valid option even in
 Although Wi-Fi technology is predominantly utilized for short-range wireless local area networks, there are notable exceptions involving long-range deployments, such as those employed by ISPs and for low-cost  \ac{P2P} remote communication. Notable extreme example of this is 279 km long unamplified Wi-Fi link in Venezuela\cite{adhocwireless}.
 
 
-% ct wifi https://www.wi-fi.org/discover-wi-fi/internet-things
 
 \subsection{Zigbee}
 
 Zigbee is a open wireless communication protocol specification, operating within the IEEE 802.15.4 standard, designed for low-bandwidth, low-power, short-range \ac{WPAN}. It is characterized by its mesh networking capabilities, which facilitate robust and scalable communication among numerous devices in close proximity. Its main application are smart home accessories and industrial sensors on sort range \cite{zigbee}.
 
 Zigbee primarily operates on 2.4 GHz band (in usual gaps between Wi-Fi channels) but can also operate on sub-GHz bands. It is similar to Z-Wave protocol.
-% ct zigbee https://www.digi.com/solutions/by-technology/zigbee-wireless-standard
-
-\subsection{Sigfox}
-
-Sigfox is a proprietary \ac{UNB} \ac{LPWAN} technology designed for low-throughput, long-range communication primarily targeting massive \ac{IoT} applications. Operating in unlicensed sub-GHz radio frequency bands, Sigfox employs an \ac{UNB} modulation scheme that enables robust communication over significant distances with extremely low power consumption. 2  This technology is particularly suited for applications involving the transmission of small, infrequent data packets, such as basic sensor readings and status updates, where extended battery life and wide coverage are paramount
-
-
 
 \section{4G IoT networks (LPWAN)}
 
-https://blog.nordicsemi.com/getconnected/what-is-cellular-iot
-https://www.nordicsemi.com/Products/Wireless/Low-power-cellular-IoT/Development-tools?lang=en\#infotabs
+%https://blog.nordicsemi.com/getconnected/what-is-cellular-iot
+%https://www.nordicsemi.com/Products/Wireless/Low-power-cellular-IoT/Development-tools?lang=en\#infotabs
 
-%IoT has become a large part of every day life and is now crucial to many both critical and non-critical applications. With planed shutdown of 2G and 3G networks [] it is important to look on protocols that are supposed to replace them and enhance their capabilities.
+IoT has become a large part of every day life and is now crucial to many both critical and non-critical applications. With planed shutdown of 2G and 3G networks \cite{ctu2g} it is important to look on protocols that are supposed to replace them and enhance their capabilities.
 
 \ac{LPWAN} protocols are 4G LTE wireless communication technologies that enable long-range transmission among IoT devices. \ac{LPWAN} protocols are designed to meet the diverse requirements of IoT applications, mainly low power consumption, wide coverage range, capacity for large number of devices, and high reliability \cite{gsmalpwan}.
 
-\colorbox{orange}{Kajsik zrcadlova $\lambda$ krivka} \\
-
 \subsection{NB-IoT}
 \ac{NB-IoT}  is a cellular \ac{LPWAN} standard that was developed by \ac{3GPP} for IoT devices and services in 2016 under \ac{3GPP} Release 13 and updated in 2017 with \ac{3GPP} Release 14 \cite{erf}.
 
@@ -141,7 +130,7 @@ As of writing this thesis (December 2023) NB-IoT is supported in Czechia by all
 
 \subsection{LTE-M}
 
-LTE-M or LTE-MTC (Long-Term Evolution Machine Type Communication) is a second \ac{LPWAN} protocol specified in \ac{3GPP} Release 12, with improved specification in Releases 13 and 14. Unlike NB-IoT, LTE-M uses more bandwidth (1.4 - 5 MHz) and is capable of higher communication speeds (1 - 4 Mbit/s for downlink and 1 – 7 Mbit/s for uplink). Another advantage of LTE-M over NB-IoT is an ability to function with movable objects (such as cars or drones). Higher bandwidths however lead to greater circuit complexity and possible higher energy consumption related to it \cite{nordiccompare}.
+LTE-M or LTE-MTC (Long-Term Evolution Machine Type Communication) is a second \ac{LPWAN} protocol specified in \ac{3GPP} Release 12, with improved specification in Releases 13 and 14. Unlike NB-IoT, LTE-M uses more bandwidth (1.4 - 5 MHz) and is capable of higher communication speeds (1 - 4 Mbit/s for downlink and 1 - 7 Mbit/s for uplink). Another advantage of LTE-M over NB-IoT is an ability to function with movable objects (such as cars or drones). Higher bandwidths however lead to greater circuit complexity and possible higher energy consumption related to it \cite{nordiccompare}.
 
 As of writing this thesis (December 2023) LTE-M is covered in Czechia by O2 in 98.5 \% \cite{o2catm} and locally by Vodafone \cite{vodafonemap}.
 
@@ -155,12 +144,10 @@ As of writing this thesis (December 2023) LTE-M is covered in Czechia by O2 in 9
 
 \section{Cellular 5G IoT networks}
 
-\colorbox{orange}{Kajsik 5G trojuhelnik}
-
 5G implementation into the mobile networks can be achieved via two methods \cite{5gnruk}:
 
 \begin{itemize}
-	\item NSA (non-stand alone) - 5G features are achieved by adding new RAN (Radio Access Network) to existing 4G LTE core. This approach implements dynamic spectrum sharing and enables rapid deployment of enhanced mobile broadband in customer market without larger changes in existing infrastructure.
+	\item NSA (non-stand alone) - 5G features are achieved by adding new \ac{RAN} to existing 4G LTE core. This approach implements dynamic spectrum sharing and enables rapid deployment of enhanced mobile broadband in customer market without larger changes in existing infrastructure.
 	\item SA (stand alone) - LTE core and RAN are completely replaced with 5G ones. RAN can however still switch back to LTE air interface to ensure backward compatibility with non-5G devices.
 \end{itemize}
 
@@ -179,8 +166,6 @@ As of December 2023, 5G IoT networks are not yet commercially available in Czech
 %%%%%%
 \subsection{URLLC requirements}
 
-\colorbox{orange}{Zestrucnit} \\
-
 URLLC (Ultra-Reliable and Low-Latency Communication) is a new requirement for 5G networks  for providing real-time communication protocols with very low delays and very high levels of reliability. First attempts to address this were introduced in 4G LTE HRLLC (Higher-Reliability and Low-Latency Communication) in \ac{3GPP} release 15 \cite{5gamericasurllc}. Until this point, aspects of latency and reliability were
 dealt in separately and sometimes were in direct contradiction to each other (reliability was achieved with repeated data redundancy, which multiplied latency). Combination of these two aspects is however essential for several critical applications with different requirements, as shown in table \ref{tab:urllc}:
 
@@ -191,10 +176,10 @@ dealt in separately and sometimes were in direct contradiction to each other (re
 			\hline
 			Scenario & E2E latency [ms] & Reliability [\%] & Data rate [Mbps] \\\hline\hline
 			Discrete automation						& 10	& 99.99		& 10 \\\hline
-			Process automation – remote control		& 60	& 99.9999	& 100 \\\hline
-			Process automation ‒ monitoring			& 60	& 99.9		& 1 \\\hline
-			Process automation ‒ monitoring			& 40	& 99.9		& 10 \\\hline
-			Electricity distribution – high voltage	& 5		& 99.9999	& 10 \\\hline
+			Process automation - remote control		& 60	& 99.9999	& 100 \\\hline
+			Process automation - monitoring			& 60	& 99.9		& 1 \\\hline
+			Process automation - monitoring			& 40	& 99.9		& 10 \\\hline
+			Electricity distribution - high voltage	& 5		& 99.9999	& 10 \\\hline
 			Intelligent transport systems				& 30	& 99.9999	& 10 \\\hline
 		\end{tabular}
 	\end{center}
@@ -224,17 +209,10 @@ Air interface is only partially responsible for total end-to-end latency. Remain
 
 Another method of lowering transport network latency is to avoid transport network completely. This is experimented in vehicle-to-vehicle (V2V) protocols and in non-IP based communication \cite{5gamericav2v}.
 
-\subsection{Cellular URLLC reliability optimization}
-
-In \ac{3GPP} Release 16, redundant transmission for high-reliability communication was introduced \cite{5gamericasurllc}. With this method, user packets are duplicated and simultaneously transferred to the receiver via two disjoint user plane paths. The redundant packets are then eliminated at the receiver side. This further avoids occasional fails in one path propagation and slims probability of exceeding the delay requirements. Other changes can be made in 5G core parameters settings, like QoS Monitoring, dynamic division of Packet Delay Budget and enhancements of session continuity \cite{3gppurllc}.
-
-\subsection{Shortcomings of cellular URLLC and time horizon}
-
 \section{DECT NR+ standard for 5G IoT networks}
 
 \subsection{Plain DECT}
 
-
 \ac{DECT} is a digital wireless technology standard primarily known for cordless telephones, though its applications have expanded to some not foreseen use-cases (professional wireless audio solutions such as walkie-talkies and wireless audio on music concerts).
 
 \ac{DECT} is an open standard that operates in a dedicated frequency range, typically 1880-1900 MHz in Europe, Asia, Australia, New Zealand, and South America, and 1920-1930 MHz in the US. This dedicated spectrum helps minimize interference from other wireless technologies like Wi-Fi and Bluetooth. 
@@ -245,6 +223,8 @@ In \ac{3GPP} Release 16, redundant transmission for high-reliability communicati
 
 \subsection{DECT NR+} \label{dectdescrition}
 
- \cite{dectnrdesc}
+\ac{DECT NR+} is an evolution of the DECT standard, developed by \ac{ETSI}. It is designed to address the requirements of \ac{IoT} in existing DECT bands. It meets the 5G requirements for \ac{mMTC} and \ac{URLLC} applications. DECT NR+ is recognized by \ac{ITU} as the world's first non-cellular 5G technology standard (however nonsensitive it may sound) \cite{etsidect}.
+
+DECT NR+ supports \ac{P2P}, star, and mesh topologies. Devices are organized into individual cluster tree topologies, called clusters. \cite{dectnrdesc} 
 
-% https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/dect-nr-a-technical-dive-into-non-cellular-5g
\ No newline at end of file
+The low latency and high reliability are done by combination of factors. The main is further division of 10 ms slots to 0.5 ms sub-slots and implementation of \ac{HARQ}. The preservation of base 10 ms slots is done to ensure backward compatibility with older DECT devices \cite{dectnrdesc}.
\ No newline at end of file