Wi-Fi and 5G 173
and it is often impossible, in these sensor networks, to use a TCP/IP or
even UDP/IP protocol stack.
For the moment, security and QoS problems are taking a back seat
to energy consumption problems. In any case, a great deal of research
is currently being done to render sensor networks efficient and robust.
The main radio standards are ZigBee, WiBree and 6LowPAN.
WiBree is a very low-consumption technology with a range of 10 m
and a data rate of 1 Mbps. This solution was developed by Nokia to
compete with both ZigBee and Bluetooth. However, it was integrated
with Bluetooth in 2009, with the resulting product being called
Bluetooth LE (Low Energy).
6LowPAN networks (IPv6 over Low power Wireless Personal
Area Networks) were proposed by a working group at the IETF. The
objective, obviously, is to facilitate continuity of IP on non-powerful
machines with limited electrical power.
The use of the IPv6 standard to obtain a very large number of
addresses for immense sensor networks poses a problem. The 16 bytes
occupied by the transmitter’s address, added to the 16 bytes of the
receiver address, plus the obligatory fields, lead to poor usage of the
radio link to transport the supervision data. This could become
genuinely problematic in light of how little energy the sensor has.
ZigBee, on the other hand, limits the length of its frame to 127 bytes,
which may also cause problems if the message supplied by a sensor
for transmission is long.
Sensors form ad hoc networks, and they need a routing protocol.
The use of a protocol such as IEEE 802.11s, in combination with IPv6
addresses, would be catastrophic for the sensors’ battery life. For this
reason, current propositions are much simpler, with protocols such as
LOAD (6LowPAN Ad hoc On-Demand Distance Vector Routing
Protocol), a simplified version of AODV, DyMO-Low (Dynamic
MANET On-demand for 6LowPAN), a simplification of DyMO, from
the MANET working group, and Hi-Low (Hierarchical Routing over
6LowPAN). These different protocols stem from propositions by the
IETF, and therefore the standardization of ad hoc networks, but they
do not include all the potential options.
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and it is often impossible, in these sensor networks, to use a TCP/IP or
even UDP/IP protocol stack.
For the moment, security and QoS problems are taking a back seat
to energy consumption problems. In any case, a great deal of research
is currently being done to render sensor networks efficient and robust.
The main radio standards are ZigBee, WiBree and 6LowPAN.
WiBree is a very low-consumption technology with a range of 10 m
and a data rate of 1 Mbps. This solution was developed by Nokia to
compete with both ZigBee and Bluetooth. However, it was integrated
with Bluetooth in 2009, with the resulting product being called
Bluetooth LE (Low Energy).
6LowPAN networks (IPv6 over Low power Wireless Personal
Area Networks) were proposed by a working group at the IETF. The
objective, obviously, is to facilitate continuity of IP on non-powerful
machines with limited electrical power.
The use of the IPv6 standard to obtain a very large number of
addresses for immense sensor networks poses a problem. The 16 bytes
occupied by the transmitter’s address, added to the 16 bytes of the
receiver address, plus the obligatory fields, lead to poor usage of the
radio link to transport the supervision data. This could become
genuinely problematic in light of how little energy the sensor has.
ZigBee, on the other hand, limits the length of its frame to 127 bytes,
which may also cause problems if the message supplied by a sensor
for transmission is long.
Sensors form ad hoc networks, and they need a routing protocol.
The use of a protocol such as IEEE 802.11s, in combination with IPv6
addresses, would be catastrophic for the sensors’ battery life. For this
reason, current propositions are much simpler, with protocols such as
LOAD (6LowPAN Ad hoc On-Demand Distance Vector Routing
Protocol), a simplified version of AODV, DyMO-Low (Dynamic
MANET On-demand for 6LowPAN), a simplification of DyMO, from
the MANET working group, and Hi-Low (Hierarchical Routing over
6LowPAN). These different protocols stem from propositions by the
IETF, and therefore the standardization of ad hoc networks, but they
do not include all the potential options.
www.it-ebooks.info