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An Overview of the IEEE 802.15.4z Standard and its Comparison to the Existing UWB Standards

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This paper focuses on the new standard of IEEE 802.15.4z, which is seeking to enhance the already existing standards for the Impulse Radio Ultra-Wideband (UWB) technology. We describe the current state in regards of standardization of the UWB technology and also the proposed changes to be made. In the last part, we compare the new enhancements to the existing standards and describe the proposed improvements to be made in ranging capabilities, power consumption and security for both HRP and LRP UWB PHYs while also naming several practical applications where these new enhancements will be used.
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An Overview of the IEEE 802.15.4z Standard and
its Comparison to the Existing UWB Standards
Petr Sedlacek1, Martin Slanina1, and Pavel Masek2
1Department of Radioelectronics, Brno University of Technology, Brno, Czech Republic
2Department of Telecommunications, Brno University of Technology, Brno, Czech Republic
Contact author’s e-mail: sedlacekp@phd.feec.vutbr.cz
Abstract—This paper focuses on the new standard of IEEE
802.15.4z, which is seeking to enhance the already existing stan-
dards for the Impulse Radio Ultra - Wideband (UWB) technology.
We describe the current state in regards of standardization of the
UWB technology and also the proposed changes to be made. In
the last part, we compare the new enhancements to the existing
standards and describe the proposed improvements to be made
in ranging capabilities, power consumption and security for both
HRP and LRP UWB PHYs while also naming several practical
applications where these new enhancements will be used.
Keywords—IEEE 802.15.4z; Ultra-Wideband; Positioning;
Power consumption
I. INTRODUCTION
The UWB standards available so far incorporate the Impulse
Radio part mainly for precise indoor tracking, but also for
secure access control of vehicles and for the automotive
industry in general. However, since the market demand for
this kind of technology is on the rise, there is an increasing
demand for improved capabilities that the current standards
cannot provide. This paves the way for a new standard called
IEEE 802.15.4z. In order to introduce this new standard, a
new formal organization called the UWB Alliance was formed.
This not-for-profit organization consists mostly of UWB sil-
icon chip manufacturers such as DecaWave or Ubisense, but
also large technology providers like Apple and Samsung and
also automotive manufacturers such as Hyundai and Kia.
The goal of the alliance is to increase the interoperability
of the UWB technology, introduce a more secure ways for
access control systems and to open its’ way into the world of
smartphones [1].
Several members of this alliance have been working on
the new 802.15.4z standard and formed an IEEE 802.15.4
Enhanced Impulse Radio (EIR) Task Group 4z. The group
intends to incorporate several improvements on the existing
standards, such as higher data throughput, higher security and
larger distances between the transceivers. One goal is to also
to promote UWB technology to the general public, so it will
become as well known as other already existing positioning
technologies, like GPS for example. Another goal is to also
introduce UWB technology in regions, where it is currently
not possible since no regulations enable its operation, such
as India for example. Finally, the Alliance aims to ensure
interoperability with new and existing Wi - Fi standards, to
ensure its members will be able to use the spectrum with no
interferences with this technology [1].
The paper is divided in three parts, the first one focuses on
a brief overview of the existing standards to give the reader
an idea on the state of the art regarding the Ultra - Wideband
technology. The second part focuses on description of the new
techniques that the standard aims to introduce and the third
part compares these new techniques to the already existing
ones to give a comment on what to expect from this new
standard.
II. STATE OF T HE ART
A. The IEEE 802.15.4a standard
In theory, UWB communication has been around for a
long time, but there was no ratified standard to ensure its
wide adoption across the world. Although a first form of
regulation of UWB technology came from the American Fed-
eral Communications Commission (FCC) in 2002, there was
no standard incorporating it into a network. This regulation
simply allowed UWB to communicate in an unlicensed fashion
in the given frequency range with a very strict power spectral
density of - 41.3 dBm / MHz to ensure that this new technology
will not interfere with already existing wireless systems in the
given band.
In 2007, the IEEE 802.15.4a standard was introduced, which
came as an addition to the original IEEE 802.15.4 standard
for WPAN networks, introducing the new UWB PHY into the
already existing WPAN standard. At that time, it introduced
a new way to achieve a power efficient and high data rate
enabled communication technology that is also capable of a
very precise ranging by utilizing UWB. This marks a first
standard for the UWB technology that could pave its way into
a worldwide use. This original standard introduced a high rate
pulse repetition (HRP) UWB PHY. However, even today there
are several countries across the world that severely limit the
use of UWB technology, either in the operating frequency or
its maximum transmission power [2].
B. Additional standards
Two more amendments were made to the original standard
of 802.15.4a. The first revision came in 2011 as a new standard
called 802.15.4 - 2011. This standard came as an addition to
the exiting ones, and the changes here were mainly editorial
rather than technical. Several PHY and MAC features were
added over the years to the original standard of 802.15.4, so
the new standard from 2011 aimed to unify all these into a
new one. In this new standard, each new PHY has its’ own
clause and a new Additional MAC is also split into several
parts [3].
There were several PHYs and MAC additions to the stan-
dard since 2011 and these were again aligned into a new
standard called 802.15.4-2015. This is yet the latest revision
of the standard to date. Part of this standard is also an
introduction of the new low rate pulse repetition (LRP) UWB
PHY. The new standard also aims to be fully compatible with
the original 802.15.4a standard [4].
III. THE N EW 802.15.4Z STANDARD AND ITS
CAPABILITIES
As already mentioned, the new IEEE 802.15.4z standard
aims to introduce new capabilities into the already existing
standards. These new and improved technical capabilities
are described in detail in the following text. The standard
introduces enhancements to improve both the LRP and HRP
UWB PHYs and also MAC changes to support the PHYs.
A. Improved Ranging
Since a very good ranging capability resulting in a highly
accurate positioning is one of the key features of UWB
technology, there is a high emphasis on enhancing these
abilities. Any UWB based ranging system is based on Time-of-
Flight (ToF) measurements, which means that the standard has
to provide reliable and robust ranging timestamps to accurately
measure the distance between devices. However, the ranging
enhancements are mainly applied to the HRP PHY, since the
current LRP has no ranging capabilities [4].
One improvement on the MAC layer incorporating the ToF
measurements is the suggested use of a single-sided two-way
ranging between devices (SS - TWR). This scheme is depicted
in Figure 1. In that scenario, Device A tries to estimate its
distance from Device B by estimating the ToF. It sends a frame
to Device B and receives a reply. Device A will then be capable
of calculating the estimated time of flight Tprop by using the
following formula:
Tprop =
Tround Treply
2
.(1)
Device B will need to communicate its reply time Treply
to Device A, but it is suggested that this could be done in a
subsequent frame. An option would be also for the MAC to
be able to pre-compute Treply [5].
This scheme simplifies calculating the ToF estimates when
compared to a symmetrical double-sided two-way ranging,
since the devices need to exchange just two messages instead
of three, like they have to now. At first glance, this may not
seem as much but this reduces the overall necessary on-air
time which saves the battery lifetime and increases the radio
channel capacity at the same time.
Another enhancement to the ranging part is called ”Simulta-
neous ranging”. This technique enables for devices to respond
at almost the same time with overlapping frames. The idea
is shown in Figure 2. Each of the responding devices has a
different delay, but the sequences can overlap. The receiver
can then lock on to one of the responders and accumulate all
the responding ciphers after receiving PHY header (PHR) and
data from the first one [6].
The idea is to reduce the the battery lifetime of the receiving
device, since it can treat all four responses from the Anchors
as a single Rx frame instead of receiving four separate frames.
This is very useful in automotive for example, where UWB
is used to precisely measure the distance between a car and a
key-fob. This use of UWB came along after the relay attack
problems with wireless car key appeared [7], [8]. The key-
fob sends a poll message to the car and the four anchor
points on the car (for example at each corner of the car)
send the response at the same time. This simultaneous ranging
method significantly increases the battery lifetime of the key-
fob. Obviously, this method requires for all the anchor points
to be precisely synchronized. There are also several variants of
the Simultaneous ranging being proposed, the one described
is the staggered variant but there can be also serial variant or a
combination of both - staggered serial variant. More on these
techniques can be found in [6].
B. Improved Timestamp Robustness and Security
This topic is somewhat related to the previous section. As it
was already mentioned, an accurate and robust determination
of the timestamp is the key factor to precise ranging estimates.
For that reason, the new IEEE 802.15.4z standard intends to in-
troduce a type of periodic preambles called Ipatov sequences.
In order to maintain backward compatibility, the PHY should
still maintain a chipping rate of 499.2 MHz and the data should
continue to use the same Forward Error Correction (FEC). The
PHR length and error correction should also remain intact [5].
The periodic sequences were chosen for their good auto-
correlation properties. The accumulation of the correlation
should ideally generate such channel impulse response (CIR)
from which the first path of the signal can be reliably deter-
mined. To improve the results even further, a cryptographically
generated sequence is inserted into the PHY frame. The
receiver will then generate its own sequence which will be
Device B
TX
Device A
RX
RX
TX
time
Tround
Treply
Tprop
Tprop
Fig. 1. Single - Sided Two-Way Ranging (SS- TWR) [5].
Ipatov preamble
Ipatov preamble
Ipatov preamble
Ipatov preamble
Silence
d+128ns
Silence
d+256ns
Silence
d+374ns
SFD
SFD
SFD
SFD
PHR
PHR
PHR
PHR
Payload
Payload
Payload
Payload
Cypher
Cypher
Cypher
Cypher
A
Cypher
B
C
D
Fig. 2. Message formats for Simultaneous ranging [6].
SYNC
SYNC
SYNC
SFD
SFD
SFD
PHR
PHR
PHR
Cipher sequence
Cipher sequence
PHY payload
PHY payload
PHY payload
Mode 0
Mode 1
Mode 2
Fig. 3. Modes for the Ciphered Messages [5].
cross correlated with the receiving one. This will produce a
CIR to get the Rx timestamp and at the same time increase the
resistance to interference because only the valid transmitters
and receivers know the key to the ciphered sequence. The
idea is to increase the integrity of the message against both
accidental and intentional (malicious) interference. The modes
for the ciphered message types are shown in Figure 3.
As shown in Figure 3, there are three suggested modes for
the frames. In Mode 0, there is no ciphered message included
in the PHY frame. In Mode 1, the message is inserted after
the start-of-frame delimiter (SFD). In Mode 2, the ciphered
sequence is inserted after the payload part. Mode 1 has the
advantage that the CIR processing can start earlier and that
it does not need to be adjusted in case of varying frame
lengths. Mode 2 on the other hand enables the messages to
be received by receiver that expect normal HRP UWB frame
format, which is important for backward compatibility. This
also allows the use of simultaneous ranging as explained in
the previous section. The proposed cryptographic scheme is
a standard AES - 128 in counter mode which should ensure
interoperability among vendors [5].
C. Reducing On-Air Transmissions
There is also a strong emphasis on reducing the total on-air
transmission times of the devices. There are several reasons
for a short transmission time and a shorter resulting frame:
Greater radio channel capacity.
Increased battery lifetime.
Lesser interference among the devices.
Increased security - smaller time window for any attacks.
One of the ideas to compress the on air time of the radio
is to use higher data rates. As per the IEEE 802.15.4-2015
standard, the highest data rates for UWB PHY are the rates
of 6.81 Mbit/s and 27 Mbit/s. Overall, the symbol time for
the UWB PHY is 128 ns for both data rates. There were
several proposals on how to enhance the existing standards
with different pulse spacing and power level. This is an
aspect that has to be carefully considered due to UWB’s
strict transmission power requirements made by regulatory
bodies [2], [9].
As per the original IEEE 802.15.4a standard, the data
symbol consists of a burst of pulses and Guard Intervals. Half
of the symbol is shown at figure 4. For a nominal PRF of
64 MHz the symbol time is 128 ns which consists of 64 2 ns
chips. Each burst has 8 pulses resulting in a 16 ns long burst of
pulses. There is also a hopping possibility for the burst as per
the used BPM - BPSK modulation, since both the phase and
the position of the burst indicate a bit of information. This
approach has some disadvantages though, one of them being
the fact that for a longer train of pulses (more than 20 ns), the
Spectral Peak to Average Power Ratio (SPAR) is very high [2],
[9].
TBPM
Possible Burst Position (Nhop)
Guard Interval
Tburst
Tc
Ncpb
Fig. 4. Half of a UWB PHY data symbol [1].
There were several proposals on how to handle this issue.
Either by increasing the spacing between the pulses and
eliminating the Guard Interval, or using a combination of
both. This could effectively eliminate the SPAR issue while
maintaining the same data rate capabilities. The idea is also to
maintain the original BPM - BPSK modulation for backwards
compatibility with the 6.8 MHz PRF. The latest agreed mode
with the highest PRF utilizes a 128 MHz PRF with 16 pulses
per coded bit using a 4 ns spacing, while maintaining the
Guard Interval, as shown in Figure 5 [10].
Tburst = 32.05 ns
Tburst = 32.05 ns
Guard Interval
(32.05 ns)
Guard Interval
(32.05 ns)
Fig. 5. Symbol format for a data rate of 6.81 Mbit/s with a PRF of
128 MHz [10].
There were also several proposals for the higher data rate
of 27 Mbit/s, where the symbol time is just 32 ns consisting of
four Guard Intervals and eight bursts with each burst consisting
of 2 pulses with a 2 ns spacing. The mode with the highest
PRF of 256 MHz has eight pulses per encoded bit with the
pulses being formed into two groups of four, each one having
its own Guard Interval [10].
Tburst = 8.01 ns
Tburst = 8.01 ns
Guard Interval
(8.01 ns)
Guard Interval
(8.01 ns)
Fig. 6. Symbol format for a data rate of 27 Mbit/s with a PRF of
256 MHz [10].
Besides using the higher refresh rates also with higher PRFs,
there are also several frame compression techniques that are
considered to further reduce the necessary on-air time. One
of the ideas is to shorten the Ipatov codes to create shorter
symbols or to reduce spreading factors in preamble sequences.
The Ipatov sequences could also use more non-zero elements
to increase the symbol energy in compensation to them being
shorter. The ciphered sequences could be further compressed
by removing the 256 zeros which form the second half of the
message [5].
D. LRP UWB PHY Enhancements
Until now, the LRP UWB PHY was not intended for ranging
applications. The goal of the new 4z standard is to enable
a new class of devices which could be used for a secure
access based on ranging capabilities. The main features for
these devices is a ultra - low power consumption and interop-
erability between manufacturers. The idea is to implement a
basic ranging scheme based on Round-Trip ToF with a fixed
processing time for the UWB LRP PHY as an amendment to
the original standard [11]. This is shown in Figure 7.
Initiator
Responder
Nv
Np
ts
tr
tp
Secure distance measurement = (tr - ts - tp)*c/2
Fig. 7. RTToF for UWB LRP PHY [11].
This will also probably incorporate changes to the MAC.
Additional change being proposed is that only the Base mode
of the LRP PHY should be mandatory, while the Extended
and Long-range modes could be optional.
The practical application for such enhancement of the LRP
UWB PHY could be again in the automotive industry, to
prevent the already mentioned Signal Amplification Relay
Attacks [8]. Of course, besides just the ranging itself the
devices would have to authenticate to make the transaction
secure. The authentication in this scheme could be either one -
way or mutual, the length of the random sequence used would
vary based on the required level of security [12], [13].
IV. COMPARISON TO PREVIOUS STANDARDS
In this section, we compare the proposed changes for the
new IEEE 802.15.4z standard when compared to the already
existing ones and bring out the key improvements and benefits
of this new amendment. We also discuss their practicality in
real applications.
A. Enhancements in the Radio
Naturally, a strong emphasis is put on enhancing the radio
capabilities of the UWB PHY. The key limiting factors for
the current UWB devices is mainly the limited range of the
radio due to very strict transmission power requirements. The
new standard tries to tackle this issue which is underlined by
the fact that directly on the main website of the EIR 4z Task
Group it states that the typical range of the radio is up to 100
meters.
If we would consider a general location system based
on UWB technology, which is one of the most common
applications for UWB, one of the limiting factors is the range
between the fixed location sensors (Anchors) and the mobile
locators (Tags) as well. Typically, the distance between the
Anchors is no more than a few tens of meters due to the
extremely low Tx power of the radio. The same goes for
the communication between the Anchors and Tags. Commu-
nication between the Anchors is even more sensitive to this
distance if we would consider a wireless synchronization in
the system. The improved timestamp formats described in this
paper could help improve the robustness of the messages and
thus improve the overall range that could be achieved.
Besides just the range, a key factor for UWB based location
systems is also the location accuracy. With the introduction of
the new enhancements, the general First Path detection should
improve helping with the reliability of the measurement and
the resulting accuracy as well.
As already explained, reducing on - air times is also one
of the key factors. The number of devices utilizing the UWB
technology is ever increasing, so it is very important to address
the issue of having multiple devices in the same collision
domain with as least interference among them as possible. The
newly introduced PRFs of 128 MHz for 6.81 Mbit/s data rate
and a PRF of 256 MHz for the 27 Mbit/s data rate should help
immensely compared to the maximum 64 MHz PRF which
is currently the maximum value. The revisions and proposals
made to the current PRFs could also increase the distances
significantly.
Overall, introducing higher PRFs, compressing the radio
messages and increasing their robustness will dramatically
increase the battery lifetime, which is a crucial factor for the
mobile Tags in any UWB based system.
B. New Ranging Features
The introduction of SS - TWR as explained would make the
ToF estimates more simple when compared to the DS - TWR
which is implemented today. For example, DecaWave notes in
one of their Application Notes regarding ranging implementa-
tion that the SS -TWR scheme cannot be implemented with the
current chips due to the instability of the oscillators making
the resulting measurement unstable and not precise [14]. If
the new generation of chips could handle this issue with the
help of the MAC changes in the new standard, this ranging
technique could be more easily implemented.
The introduction of the new Simultaneous ranging capability
is also interesting for several use cases. The most typical one
which is brought up most often is the wireless car key access.
With this technique enabled, the receiving key-fob would be
able to simultaneously handle incoming responses from several
Anchors, which will dramatically increase battery lifetime.
Generally, putting the UWB radio in a receiving state has a
big impact on the battery so any reduction of this is a big
advantage.
C. Security
Security was not a big topic in the previous UWB standards,
most likely because the technology was still new and because
of the low transmission power levels, it appears a general
radio noise to non-UWB devices. However, with a proper
UWB sniffing devices, it is currently very easy to intercept
any UWB communication on the given channel, if the vendor
of the system does not have some sort of custom encryption
implemented.
Because UWB technology is finding more and more ap-
plications in the automotive industry for example and also
becoming more and more ubiquitous at the same time, security
of the technology has become a very important topic. That is
why the new standard implements several ways to increase the
security among the wireless transactions. One of them is the
introduction of the new ciphered messages between commu-
nicating devices, which require a form of authentication key
to prevent any malicious form of communication. The overall
Security is also increased thanks to the reduced on - air time
of the radio and shorter messages.
Big emphasis is also on providing highest security possible
for the UWB LRP PHY, which is newly intended for ranging
applications as well enabling secure access to vehicles for
example. The LRP PHY shall also utilize a form of authenti-
cation, either a one - way or a mutual one.
D. Overall Comparison
We made a summary of all the major changes made to
the UWB standards over the years including the new IEEE
802.15.4z standard. The changes are summarized in the fol-
lowing table:
It is clear from the table that the new IEEE 802.15.4z
standard has the biggest impact on UWB technology since
TABLE I
COMPARISON BETWEEN THE STANDARDS
Standard Major Changes
IEEE 802.15.4a Introduction of the UWB PHY
First standardization of UWB
IEEE 802.15.4 - 2011 Mainly editorial changes
IEEE 802.15.4 - 2015
Introduction of the LRP UWB PHY
Introduction of the HRP UWB PHY
Full backwards compatibility
IEEE 802.15.4z
Enhanced Ranging with SS - TWR
Introduction of Simultaneous Ranging
Introducing ciphered sequences
Introduction of higher PRFs
Enabling ranging for LRP UWB PHY
High increase of security for both PHYs
the introduction of the IEEE 802.15.4a standard back in 2007.
The standards released in 2011 and 2015 introduced only
small changes and enhancements when compared to the new
standard.
The changes and enhancements proposed in this standard
clearly take into account the most typical applications of UWB
technology today and it seeks to improve these in several ways.
High emphasis is put mainly on increasing battery lifetime,
increasing the available number of Tags in the given area and
increasing security. All of these aspects will be of extreme
importance with the increasing number of active UWB devices
worldwide.
V. CONCLUSION
This paper describes the new IEEE 802.15.4z standard
which is aiming to be ratified during the course of 2019. We
have looked at some of the enhancements that this standard
brings to the current UWB PHY and MAC for both LRP and
HRP UWB PHYs. In the first part, we tried to focus mainly
on the current state in terms of standardization in the UWB
world and sum up all of the important changes that were made
by subsequent amendments and standards to the original one
from 2007.
In the second part, we tried to look more closely on some
of the proposed changes for the new standard which take into
account some of the weaker points that the current UWB
technology has. These features are described in more detail
with both technical description and some examples of practical
applications where these new enhancements will be used.
In the final part, we focused on comparing the new en-
hancements to the existing standards, to see exactly where
the UWB technology can benefit with these new features
being introduced, again with several practical examples of
real applications. What we can see is that the new standard
brings along several important enhancements, which take into
consideration the fact that the presence of UWB technology
is ever increasing, and this new standard is obviously hoping
to prepare the technology for a massive increase in its use of
over the coming years, while maintaining compatibility with
the already existing standards.
ACKNOWLEDGMENT
The described research was supported by the National
Sustainability Program under grant LO1401. For the research,
the infrastructure of the SIX Center was used. The described
research was financed by the Ministry of Industry and Trade
of Czech Republic project No. FV20487.
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... Another reason is the standardization of a Ultra wideband (UWB) physical layer in the IEEE 802.15.4 standard for low-rate wireless personal area networks [10], an IoT technology, and the subsequent availability of affordable, off-the-shelf transceivers from manufacturers, such as Decawave [11]. This trend continues with the forecast of IEEE 802.15.4z [12] promising increased data rate, longer range, lower energy consumption and higher security for new applications. This revision is being promoted by the UWB Alliance, a non-profit organization seeking to increase user-awareness of UWB as an alternative to GPS for indoor use. ...
... This process is illustrated in Figure 18. We limit our experiments to a subset of the sizes generated by this process: 0, 4,12,16,32,52,60,80,88,112,124,156,172,208,216,256,276,316,360,368,376,388, 396 and 400 cells. Increasing the size of the network by adding cells to the grid border results in a non-linear increase of data transmission in the network to carry data to the sink due to multi-hop communications. ...
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In this paper, we present and evaluate an ultra-wideband (UWB) indoor processing architecture that allows the performing of simultaneous localizations of mobile tags. This architecture relies on a network of low-power fixed anchors that provide forward-ranging measurements to a localization engine responsible for performing trilateration. The communications within this network are orchestrated by UWB-TSCH, an adaptation to the ultra-wideband (UWB) wireless technology of the time-slotted channel-hopping (TSCH) mode of IEEE 802.15.4. As a result of global synchronization, the architecture allows deterministic channel access and low power consumption. Moreover, it makes it possible to communicate concurrently over multiple frequency channels or using orthogonal preamble codes. To schedule communications in such a network, we designed a dedicated centralized scheduler inspired from the traffic aware scheduling algorithm (TASA). By organizing the anchors in multiple cells, the scheduler is able to perform simultaneous localizations and transmissions as long as the corresponding anchors are sufficiently far away to not interfere with each other. In our indoor positioning system (IPS), this is combined with dynamic registration of mobile tags to anchors, easing mobility, as no rescheduling is required. This approach makes our ultra-wideband (UWB) indoor positioning system (IPS) more scalable and reduces deployment costs since it does not require separate networks to perform ranging measurements and to forward them to the localization engine. We further improved our scheduling algorithm with support for multiple sinks and in-network data aggregation. We show, through simulations over large networks containing hundreds of cells, that high positioning rates can be achieved. Notably, we were able to fully schedule a 400-cell/400-tag network in less than 11 s in the worst case, and to create compact schedules which were up to 11 times shorter than otherwise with the use of aggregation, while also bounding queue sizes on anchors to support realistic use situations.
... Most UWB overview papers focus on physical layer aspects. The authors of [7] give an overview of the IEEE 802.15.4z standard by looking into the changes that have been made to improve upon limitations of the IEEE 802.15.4 standard. The paper describes the improved ranging, improved timestamp robustness, improved security and reduced onair transmission in more detail in a technical way, while also providing examples of how these features can be used. ...
... This paper provides a comprehensive overview of the different standards that are defined for UWB communication. While previous papers [7]- [9] focused on the enhancements in security and accuracy from the IEEE 802.15.4 to IEEE 802.15.4z standard, this paper focuses on the implications for compatibility at the PHY layer and the MAC and upper layers. For each of these layers, an overview of the different standards that are defined for that specific layer is given as well as the consequences for the compatibility that the differences between the standards have. ...
Preprint
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The increasing popularity of ultra-wideband (UWB) technology for location-based services such as access control and real-time indoor track\&tracing, as well as UWB support in new consumer devices such as smartphones, has resulted in the availability of multiple new UWB radio chips. However, due to this increase in UWB device availability, the question of which (industry) standards and configuration factors impact UWB interoperability and compatibility becomes increasingly important. In this paper, the fundamentals of UWB compatibility are investigated by first giving an overview of different UWB radio chips on the market. After that, an overview of UWB standards and standardisation entities is given. Next, this overview is used to discuss the focus of these different standards and to identify the differences between them. We describe compatibility issues and associated interoperability aspects related to PHY, MAC, and upper layers. For the PHY layer, compatibility is possible for all UWB chips if the correct settings are configured. For the MAC layer, the implementation of the multiple access scheme as well as the localization technique is mostly proprietary. For the device discovery, several standards are currently being drafted. Finally, future challenges related to UWB interoperability are discussed.
... 15.4z-2020 standard [21] provides measures to reduce these effects. Next to many improvements in the allowable Physical Layer (PHY) configuration [22,23] and reduced ranging times [24], another cryptographic spreading sequence, Scrambled Time Sequence (STS) is introduced to detect and mitigate erroneous TOA estimation [25][26][27]. Figure 1. ...
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The rise of precise wireless localization for industrial and consumer use is continuing to challenge a significant amount of research. Recently the new ultra-wideband standard IEEE 802.15.4z was released to increase both the robustness and security of the underlying message exchanges. Due to the lack of accessible transceivers, most of the current research on this is of theoretical nature though. This work provides the first experimental evaluation of the ranging performance in realistic environments and also assesses the robustness to different sources of interference. To evaluate the individual aspects, a set of three different experiments are conducted. One experiment with realistic movement and two additional with targeted interference. It could be shown that the cryptographic additions of the new standard can provide sufficient information to improve the reliability of the ranging results under multi-user interference significantly.
... The IEEE 802.15 group has recently published the new standard 802.15.4z [237]. This document is an evolution of 802.15.4-2015, with improved ranging and communication functions over longer distances (up to 100 m), higher Pulse Repetition Frequencies (PRF) for extended capacities, as well as higher PHY security [67]. The stronger security and better ranging accuracy of 802.15.4z, might convert this new standard into a valuable tool in combination with other wireless methods. ...
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The industrial environment poses strict requirements to the infrastructure of good and service production and delivery. Communications are not an exception. Wired systems currently dominate in factory premises for their robustness in complex and noisy propagation conditions. They also present ruggedness in front of malicious attackers aiming to bring the communication system down or take over the system under control. Unfortunately, wired systems have severe maintenance, scalability, and operational flexibility limitations. Wireless systems constitute a solution, but they show performance weaknesses in reliability and security. This paper analyzes the security challenges of radio-frequency wireless systems in industrial use cases and aligns different categorization efforts from various sources, focusing on the lower layers of the OSI model (PHY/MAC). The analysis includes a detailed taxonomy of attacks and PHY/MAC countermeasure techniques required to make security compatible with the system requirements of industrial applications. Among the different industrial applications, the focus of this work is directed towards Factory Automation. Finally, based on the wide range of existing attacks and techniques, we propose a methodology for dissecting attack scenarios and designing tailored protection techniques and architectures. A wide diversity of attack situations are described, and the corresponding countermeasures are discussed. Finally, we propose a methodology for dissecting attack scenarios and designing tailored protection techniques and architectures.
... While the DW1000 chip is still based on the outdated IEEE 802.15.4-2011, the 2015 extension of the standard and the new version 802.15.4z offer many improvements for ranging. In particular, the introduction of security features such as encryption and improved energy efficiency through the use of techniques such as Low Rate Pulse Repetition (LRP) will make UWB technology even more attractive in the future [36] [18,44] [27]. ...
Preprint
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In the scope of this paper, the precise positioning of objects with the help of Ultra Wide Band technology is evaluated. To achieve this, a prototype module for the use with the Decawave transceiver DW1000 was implemented and added to FruityMesh, an Internet of Things (IoT) mesh network of the company M-Way Solutions. The focus of the network is low-power communication based on Bluetooth Low Energy (BLE). This includes, for example, Building Automation, Lighting Management and Asset Tracking. Especially the last stated point benefits from a position tracking as precise as possible and a long battery life. Therefore, FruityMesh is used to perform a signal-strength based localization with the existing BLE messages. Due to absorption, interference, and diffraction, these measurements tend to fluctuate and allow a positioning accuracy within 1.5m. With the integration of Ultra Wide Band and the Time of Arrival (ToA) method, a centimeter-precise localization was made possible in the course of this work, which at the same time causes only small additional costs in general. Since the connection of extra hardware is associated with decreased energy efficiency, an algorithm for optimizing the control was first developed and then tested against the created scenarios. In addition to the motion-based control of the hardware, various configurations and adjustments were analyzed to reduce the power consumption by Ultra-Wideband (UWB) transmission. Finally, the developed prototype was compared with a realistic reproduction of the existing Asset Tracking to evaluate the benefits for the use in the productive application.
... It can be suitable to support the communication demands of low-power applications onboard airplanes [272] as well as UAVs. The recent IEEE standard, 802.15.4z, propose enhanced positioning capabilities along with lower on-air transmission times [292]. ...
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Electrification turned over a new leaf in aviation by introducing new types of aerial vehicles along with new means of transportation. Addressing a plethora of use cases, drones are gaining attention and increasingly appear in the sky. Emerging concepts of flying taxi enable passengers to be transported over several tens of kilometers. Therefore, unmanned traffic management systems are under development to cope with the complexity of future airspace, thereby resulting in unprecedented communication needs. Moreover, the increase in the number of commercial airplanes pushes the limits of voice-oriented communications, and future options such as single-pilot operations demand robust connectivity. In this survey, we provide a comprehensive review and vision for enabling the connectivity applications of aerial vehicles utilizing current and future communication technologies. We begin by categorizing the connectivity use cases per aerial vehicle and analyzing their connectivity requirements. By reviewing more than 500 related studies, we aim for a comprehensive approach to cover wireless communication technologies, and provide an overview of recent findings from the literature toward the possibilities and challenges of employing the wireless communication standards. After analyzing the network architectures, we list the open-source testbed platforms to facilitate future investigations. This study helped us observe that while numerous works focused on cellular technologies for aerial platforms, a single wireless technology is not sufficient to meet the stringent connectivity demands of the aerial use cases. We identified the need of further investigations on multi-technology network architectures to enable robust connectivity in the sky. Future works should consider suitable technology combinations to develop unified aerial networks that can meet the diverse quality of service demands.
... In recent years a great interest has been shown in UWB localization technology, demonstrated by the definition of the IEEE 802.15.4 standard for precision ranging [1]. The main reason is that its peculiar characteristics are suitable for high accuracy real time indoor localization [2]. ...
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The goal of this paper is to present a compact low-cost and low-power prototype of a pulsed Ultra Wide Band (UWB) oscillator and an UWB elliptical dipole antenna integrated on the same Radio Frequency (RF) Printed Circuit Board (PCB) and its digital control board for Real Time Locating System (RTLS) applications. The design is compatible with IEEE 802.15.4 high rate pulse repetition UWB standard being able to work between 6 GHz and 8.5 GHz with 500 MHz bandwidth and with a pulse duration of 2 ns. The UWB system has been designed using the CST Microwave Studio transient Electro-Magnetic (EM) circuit co-simulation method. This method integrates the functional circuit simulation together with the full wave (EM) simulation of the PCB’s 3D model allowing fast parameter tuning. The PCB has been manufactured and the entire system has been assembled and measured. Simulated and measured results are in excellent agreement with respect to the radiation performances as well as the power consumption. A compact, very low-power and low-cost system has been designed and validated.
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In a mmWave mobile device, power consumption resulting from the high sampling rate is a primary concern for angle of arrival (AoA) estimation solutions. In this paper, we provide a power scalable solution for AoA estimation with structured waveforms in a narrowband channel. We design a set of pilot sequences that maintain orthogonality in sub-Nyquist sampling domains. We leverage the sequences’ structure to develop a variable rate decoupling algorithm to separate multiple sources at the receiver using partial knowledge about the pilots. The decoupling enables a feasible, low-complexity AoA estimation for digital architectures with flexible antenna array design. In this paper, we provide one such AoA estimation solution named ADELA for a linear antenna array design. Simulation results show that AoA estimation performance reaches the Cramer-Rao-Bounds (CRBs) for a range of SNRs. The proposed estimator with subsampling factors of 8 or less outperforms two examples of full rate virtual array AoA estimators for unknown waveforms: 2-level nested array and coprime filter bank estimators. Compared to these two examples of virtual array, our method offers an 8 times lower ADC power consumption, and a significantly lower computational complexity.
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In our modern society comfort became a standard. This comfort, especially in cars can only be achieved by equipping the car with more electronic devices. Some of the electronic devices must cooperate with each other and thus they require a communication channel, which can be wired or wireless. In these days, it would be hard to sell a new car operating with traditional keys. Almost all modern cars can be locked or unlocked with a Remote Keyless System. A Remote Keyless System consists of a key fob that communicates wirelessly with the car transceiver that is responsible for locking and unlocking the car. However there are several threats for wireless communication channels. This paper describes the possible attacks against a Remote Keyless System and introduces a secure protocol as well as a lightweight Symmetric Encryption Algorithm for a Remote Keyless Entry System applicable in vehicles.
Conference Paper
In our modern society, comfort became a standard. This comfort, especially in cars can only be achieved by equipping the car with more electronic devices. Some of the electronic devices must cooperate with each other and thus they require a communication channel, which can be wired or wireless. In these days, it would be hard to sell a new car operating with traditional keys. Almost all modern cars can be locked or unlocked with a Remote Keyless System. A Remote Keyless System consists of a key fob that communicates wirelessly with the car transceiver that is responsible for locking and unlocking the car. However there are several threats for wireless communication channels. This paper describes the possible attacks against a Remote Keyless System and introduces a secure protocol as well as a lightweight Symmetric Encryption Algorithm for a Remote Keyless Entry System applicable in vehicles.
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