FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention: RADIO FREQUENCY POWER OPTIMIZATION
2. Applicant(s)
NAME NATIONALITY I ADDRESS
TATA CONSULTANCY Indian Nirmal Building, 9th Floor, Nariman Point,
SERVICES LIMITED Mumbai, Maharashtra 400021, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

TECHNICAL FIELD
[0001] The present subject matter, in general, relates to power optimization, and in
particular, to systems and methods for radio frequency power optimization.
BACKGROUND
[0002] With the advent of wireless technology, communication between two nodes
located at distant locations has evidently become easier and efficient. The nodes typically communicate through a transceiver. The transceiver may enable a first node to transmit information, in the form of data packets, to another node, such as a second node. For instance, in smart meter technology, a smart meter installed at a location of consumption of resources, such as electricity, water, and gas typically communicates with a master node over a radio frequency (RF) channel. The smart meter is typically integrated with a RF transceiver configured to enable the smart meter to communicate with the master node over a low power RF protocol, such as ZigBee, wireless M-Bus, and Z-wave. Further, the smart meter is configured to record and send readings of consumption of the resources to a data collector, such as a server over the RF channel. The server collects the readings of consumption from the smart meter and generates a report having consumption details for consumers of the resources.
[0003] Typically, the smart meters are installed at remote locations, such as water
tanks, gas chambers, gas tankers, and electric poles. Due to the remote location of the smart meters, providing power supply to the smart meters through electric power lines may become a little complex. Therefore, in the remote locations typically battery operated smart meters may be installed. Further, in order to reduce costs and manual intervention, a battery with a long life in the range of about 15 to 20 years is installed for the operation of the smart meters. Apart from general working of the smart meter, power provided through the battery is also consumed for providing radio frequency (RF) power to the smart meter to perform a successful communication with the master node. Thus, in order to reduce the power consumption of the smart meter, the RF power of the smart meter is generally fixed at a predefined power level at which power consumption of the smart meter is optimum. However, due to variation in RF power required for the communication between nodes, the predefined

power level may be not sufficient enough to transmit the data packets from the smart meter to the master node.
SUMMARY
[0004] This summary is provided to introduce concepts related to optimizing power
consumed during communication between two nodes and concepts are further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
[0005] In one embodiment, the method comprises determining a first total power
consumed in successfully transmitting a predefined number of test packets at a first power level. The first total power includes total power consumed in transmitting the predefined number of test packets and estimated power for transmitting a first set of lost test packets at the first power level. Further, a second total power consumed in successfully transmitting the predefined number of test packets at a second power level is determined. The method further comprises comparing the first total power with the second total power. Further, an optimum power level for transmission of data packets between the two communicating nodes is ascertained based on the comparison.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The detailed description is provided with reference to the accompanying
figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.
[0007] Fig. 1 illustrates a network environment implementing a power optimization
system, in accordance with an embodiment of the present subject matter.
[0008] Fig. 2 illustrates components of the power optimization system, in accordance
with an embodiment of the present subject matter.
[0009] Figs. 3(a) and 3(b) illustrate a method for optimizing power required for
communication between nodes, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION
[0010] Smart devices, such as smart meters and smart sensors have capability of
communicating data to a server. The smart devices located at remote locations may communicate with a server to share data, such as operational data related to the smart devices. The smart devices may thus act as a first node configured to record data related to meter readings and transmit the recorded data to a second node, such as the server. While the second node may be configured to receive and process the data received from the first node. The server may thus act as a data collector configured to receive and store data from the smart devices. Further, the first node is typically connected to a battery configured to provide power to the first node for various purposes, such as for transmitting data packets, having the data, to the second node. Typically, the data packets are transmitted by a transceiver connected to the first node and powered using the battery to transmit the data packets at a predefined level of power, such as radio frequency (RF) power. In order to ensure a successful transmission of the data packets, the predefined level of power may be set at a level greater than an optimum power level required for the successful transmission. Transmitting the data packets at a high power level may result in consumption of extra power thus reducing operational life of the battery connected to the node. Further, in cases where the predefined power level is below a required power level then there may be a link failure between the first node and the second node due to which sorrie or all of the data packets may be lost in the transmission. Lost data packets, in such a case, may thus be retransmitted by the first node. The retransmission of lost data packets thus increases the power consumed in achieving the successful transmission of each of the data packets thus reducing the battery life of the battery.
[0011] In one implementation, instead of retransmitting the lost data packets to the
other node, the power level of the first node may be increased to a next level and complete set of data packets may be transmitted to the second node. In such cases, it is possible that transmitting the complete set of packets at the new level will consume more power. Therefore, the power level should be set to the optimum power level at which successful communication is achieved and the power consumed is reduced.
[0012] The present subject matter discloses a system and a method for optimizing RF
power required during communication between two nodes communicating over a wireless

network. Data communication between two nodes, i.e., a first node and a second node typically requires the nodes, say, the first node to transmit data packets at a predefined power level. For instance, in a smart metering environment the first node, such as a smart meter may be configured to transmit data packets to the second node, such as a server at the predefined power level of RF power. As will be understood, the smart meters may be installed at remote locations, such as storage and transmission points of resources, such as water, gas, and electricity. For instance, the smart meter may be installed in water tanks, gas chambers, gas tankers, and at electric poles. Further, the smart meter may be configured to record and transmit data, such as readings of consumption of the resources to the server. The server may be defined as a data collecting node configured to receive and store the data transmitted from the smart meter in the form of data packets.
}0013] In one implementation, the smart meter may be initially configured to transmit
the data packets at the predefined power level equal to a lowest power level. The lowest power level may be defined as the power level beyond which the transmitting power provided to an RF circuitry, such as an RF transceiver installed in the smart meters can not be reduced without affecting successful transmission of the data packets. In one implementation, the smart meter transmits a predefined number of test packets to the server at the lowest power level. The test packets may be a plurality of data packets containing information to be transmitted. The server, on receiving one or more of the test packets, transmits an acknowledgement corresponding to each of the received test packets to the smart meter, thus confirming the receipt of one or more of the test packets. In case no acknowledgement is received by the smart meter, the lowest power level may be increased by one power level and the test packets can be retransmitted at the increased power level. The process of increasing the power levels may be repeated until at least one acknowledgement is received by the smart meter node. The power level at which at least one acknowledgment is received may then be taken as a first power level. In case, not a single acknowledgment is received at a maximum power level, an error signal may be generated. The maximum power level may be defined as the power level beyond which power applied to the RF circuitry cannot be increased.
[0014] Further, the acknowledgements received may be analyzed to determine a
number of lost test packets. The lost test packets may be defined as the test packets which fail to reach the server, i.e., the test packets that are not transmitted successfully to the server due

to which a corresponding acknowledgment is not received by the smart meter. If the number of lost test packets is zero, the power level at which the test packets were transmitted may be taken as an optimum power level. In case, the number of lost test packets is greater than zero, a first set of lost test packets, i.e., the test packets lost at the first power level are identified. Further, estimated power required for transmission of the fif st set of lost test packets may be determined. The estimated power may be defined as the power required for successfully transmitting the first set of lost test packets. A first total power, i.e., the total power consumed in successful transmission of test packets at the first power level may be subsequently determined. In one implementation, the first total power may be determined as a sum total of power consumed in transmitting the test packets at the first power level and the estimated power for transmitting the first set of lost test packets at the first power level.
[0015] Once the first total power is determined, the power used in the transmission of
test packets may be increased to from the first power level to a next level, i.e., a second power level. The test packets may be further transmitted at the second power level to determme the optimum power level. A second set of lost test packets, i.e., the test packets lost in/during transmission of the test packets at the second power level may be subsequently determined. Further, a second total power may be determined based on the power consumed in transmitting the test packets at the second power level and estimated power required for retransmitting the second set of lost test packets at the second power level.
[0016] Further, the first total power and the second total power consumed in
successful transmission of the test packets may be compared to determine the optimum power level. In case the first total power is less than the second total power, the first power level may be ascertained as the optimum power level. On the other hand, if the first total power is greater than the second total power level, the power level for transmission may be increased from the second power level to a next power level, for example, a third power level. The test packets may then be transmitted at the third power level to determine third total power consumed in successfully transmitting the test packets at the next power level. A comparison between the third total power and the second power may be performed to determine the optimum power level. If the second power is less than the third power level, the second power level may be ascertained as the optimum power level. Else, the power is incremented from the third power level to the next power level and whole process of transmitting the test packets

and identifying the total power consumed in successful transmission of test packets at the next power levels may be repeated. The next power level may be defined as an increased power level obtained upon increasing the previous power level by one level
[0017] The above process of comparing the power required for successful
transmission at a higher power level and a lower power level may be continued up to a maximum power level until either the power required at the lower power level is less than the power required at the higher power level or a power level at which no test packet is lost is reached. The maximum power level may be defined as the power level above which the power applied for transmission of data packets may not be increased. Comparing the power used in transmission at the various power levels enables the system to transmit the data packets without wasting RF power. For instance, the system helps identify scenarios where the successful transmission of test packets at the second power level may consume more power than successfully transmitting test packets at the first power level irrespective of number of iterations from transmission of data packets lost during initial transmission at the first power level. Thus comparing the power consumed at different power levels helps in identifying the optimum power level more efficiently and accurately.
[0018] The system and method of the present subject matter thus facilitate in
ascertaining an optimum RF power level to improve life of the battery responsible for functioning of a communicating node. The comparison between the powers consumed in transmitting the data packets at different power levels helps in successful transmission of data packets using minimum RF power. The present subject matter also helps in reducing the manual intervention in ascertaining the optimum RF power level. The reduction in manual intervention and increase in the battery life further facilitates reduction of the operational cost of the communicating nodes.
[0019] Although the description herein is with reference to the smart meters and the
server in a smart metering environment, it will be understood that the present subject matter may be implemented for any nodes communicating in a communication network.
[0020] These and other advantages of the present subject matter would be described in
greater detail in conjunction with the following figures. While aspects of described systems and methods for ascertaining an optimum RF power in communication between two nodes

can be implemented in any number of different computing systems, environments, and/or configurations, the embodiments are described in the context of the following exemplary system (s).
[0021] Fig. 1 illustrates a network environment 100 implementing power optimization
systems 102-1, 102-2,..., 102-N, collectively referred to as the power optimization system 102 in accordance with an embodiment of the present subject matter. In one implementation, the network environment 100 can be a public network environment, including thousands of personal computers, laptops, various servers, such as blade servers, electronic devices, such as sensors and meters and other computing devices. In another implementation, the network environment 100 can be a private network environment with a limited number of personal computers, servers, laptops, electronic devices, such as sensors and meters, and other computing devices. In yet another implementation, the network environment 100 can be a smart environment including one or more smart sensing devices and servers.
[0022] The power optimization system 102, hereinafter referred to as the system 102,
may be implemented as any of a variety of conventional electronic devices, such as a sensing device; a smart meter; and computing devices, including, servers, a desktop personal computer, a notebook or portable computer, and a laptop. For example, the system 102 may be configured to act as a smart meter operating in a smart environment. The system 102 may thus be configured to determine readings, i.e., value or something similar of consumption of resources, such as water, electricity, and gas provided to the users. Further, the system 102 may send the reading to other devices included in the network environment 100.
|0023] Further, the system 102 is communicatively connected to a server 104 through
a network 106. The server 104 is further capable of sending and receiving data packets during a communication with the system 102. In one implementation, the server 104 may be configured to exchange, with the system 102, data packets having system data, such as the readings of consumption of the resource related to the system 102. Further, the server 104 may be configured to generate user reports having various useful information, such as the system data, billing details, and user information. For instance, in the previous example of smart environment, the server 104 may be configured to act as a server or a data collector in the smart meter environment. The server 104 may thus be configured to transmit and receive

data packets having the consumption reading of resources and subsequently prepare reports having details of the readings. The system 102 and the server 104 may thus act as a first node and a second node, respectively, communicating and exchanging data with each other over the network 106.
[0024] Further, the server 104 is communicatively connected to a plurality of user
devices 108-1, 108-2... 108-N, collectively referred to as user devices 108 and individually referred to as a user device 108, through the network 106. In one implementation, a plurality of users, such as customers and system administrators may use the user devices 108 to communicate with the server 104 for obtaining information received from the system 102. The user devices 108 may be implemented as any of a variety of conventional computing devices, including, servers, sensors, a desktop personal computer, a notebook or portable computer, and a laptop. In another implementation, the various components of the system 102 may be implemented as a part of the same computing device.
[0025] Further, the server 104 may be connected to the user devices 108 and the
system 102 over the network 106 through one or more communication links. The communication links between the system 102, the server 104, and the user devices 108 are enabled through a desired form of communication, for example, via dial-up modem connections, cable links, digital subscriber lines (DSL), wireless or satellite links, or any other suitable form of communication.
[0026] The network 106 may be a wireless network, a wired network, or a
combination thereof. The network 106 can also be an individual network or a collection of many such individual networks, interconnected with each other and functioning as a single large network, e.g., the Internet or an intranet. The network 106 can be implemented as one of the different types of networks, such as intranet, local area network (LAN), wide area network (WAN), the internet, and such. The network 106 may either be a dedicated network or a shared network, which represents an association of the different types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), etc., to communicate with each other. Further, the network 106 may include network devices, such as network switches, hubs, routers, for providing a link between the system 102 and the user devices 108. The network devices

within the network 106 may interact with the system 102, the user devices 108, and the server 104 through the communication links.
[0027] The system 102 according to an embodiment of the present subject may be
configured to transmit a predefined number of test packets to the server 104 at a predefined power level. The test packets may be defined as data packets having some predefined information to be transmitted to the server 104 to determine whether the predefined power level is optimum for the communication or not. For example, in the previous example of smart environment, the system 102 acting as the smart meter may transmit test packets having readings of consumption of the resources to the server in the smart metering environment. In one implementation, the system 102 may be configured to set a power level of a RF circuitry at a lowest power level. In one implementation, the lowest power level may be defined as the level of power below which the power required for the RF circuitry cannot be reduced for transmission of test packets. In another implementation, the lowest power level may be defined as the power level at which the system 102 is currently transmitting the test packets. The system 102 may subsequently transmit the test packets to the server 104. The server 104, on receiving one or more test packets, may transmit an acknowledgment corresponding to each of the received test packets to the system 102. On receiving the acknowledgement corresponding to the one or more of the test packets, the system 102 may ascertain the power level as a first power level. In one implementation, the first power level may be defined as a power level at which at least one acknowledgment corresponding to the test packets is received by the system 102.
[0028] However, in case the system 102 does not receive any acknowledgement
corresponding to the test packets transmitted, the system 102 may increase the lowest power level to the next power level and retransmit the predefined number of test packets at the increased power level. The system 102 may thus repeat the process of increasing the power level to the next power level until at least one acknowledgment is received from the server 104. The power level at which at least one acknowledgment is received corresponding to the predefined number of test packets may then be determined as the first power level.
[0029] Further, the system 102 may be configured to determine a number of lost test
packets, i.e., the packets, from among the test packets transmitted to the server 104, for which

no acknowledgment is received by the system 102. In one implementation, the system 102 may be configured to determine the number of lost test packets based on the number of acknowledgments received. If the system 102 identifies that the number of lost test packets is zero, the system 102 may determine the first power level as the optimum power level. However, in case the number of lost test packets is greater than zero, the system 102 may identify a first set of lost test packets. The first set of lost test packets may be defined as the packets lost during transmission of the test packets at the first level. Further, the system 102 may estimate the power required for transmitting the first set of lost test packets at the first power level. The system 102 may then determine a first total power consumed in successful transmission of the test packets at the first power level. In one implementation, the system 102 may determine the first total power based on the power consumed for transmitting the test packets at the first power level and the estimated power determined for transmitting the first set of lost test packets.
[0030] Further, the system 102 may increase the power by one level, from the first
power level to a next power level, i.e., the second power level. The system 102 retransmits the test packets to the server 104 at the second power level. The system 102 may subsequently identify a second set of lost test packets. The second set of lost test packets may be defined as test packets lost during transmission of the test packets at the second power level. The system 102 may subsequently estimate power required for transmitting the second set of lost test packets at the second power level. The system 102 may further determine a second total power consumed in successful transmission of the test packets at the second power level. In one implementation, the second total power may include estimated power determined for transmitting the second set of lost test packets and the power for transmitting the test packets at the second power level.
[0031] Further, the system 102 includes an analysis module 110 to identify the
optimum power level for further communication of data packets. The analysis module 110 may be configured to compare the first total power and the second total power to determine the power level at which minimum power is consumed in successful transmission of the test packets. In one implementation, the analysis module 110 may ascertain, based on the determination, the first power level as the optimum power level if the first total power is less than the second total power. On the other hand, if the second total power is less than the first

total power, the analysis module 110 may compare the second total power with total power consumed in transmitting the test packets at a next power level. For instance, the system 102 may increase the power by one level from the second power level to a third power level and compare the second total power with total power consumed in transmitting the test packets at the third power level. In one implementation, the process of increasing the level of power from a lower power level to a higher, i.e., a next power level and comparing the power required for transmitting test packets at both the levels is repeated whenever power consumed in successful transmission at the higher level is less then the lower level. For example, if the total power for successful transmission of test packets at the third power level is less than the total power at the second power level, the total power at the third level may be compared with total power at a fourth power level. The system 102 may thus increase the power to the next power levels, such as a fourth power level and a fifth power level up to a maximum power level. The maximum power level may be defined as the power level up to which level of power can be increased for transmission of data packets. On the other hand, whenever power consumed in successful transmission at the lower level is less then the higher level, the lower power level may be ascertained as the optimum power level.
[0032] Further, if at a particular power level not even a single test packet is identified
as the lost test packet, the analysis module 110 may ascertain the particular power level as the optimum power level. For instance, in the previous example of smart environment let us assume that the smart meter transmits 50 test packets to the server 104 at the first power level. The server 104, however, receives only 40 test packets from among the 50 test packets sent to the server 104. The server 104 may thus send acknowledgments corresponding to each of the 40 test packets to the smart meter. Thus, the smart meter may estimate the power that may be consumed in retransmitting the remaining 10 test packets at the first power level. The Smart meter may further determine the total power consumed in transmitting the 50+10 test packets. Further, the 50 test packets may be transmitted to the server 104 at the second power level and total power consumed in successful transmission of the test packets at the second power level may be calculated in a way similar to the determination of the total power at the first power level. If the power consumed at the first power level is less than the power consumed at the second power level, the analysis module 110 may ascertain the first power level as the optimum power level. Otherwise, the process of comparison may be performed

until either the power required at a lower power level is less than the power required at a higher power level or a power level, at which no test packet is lost, is reached.
[0033] For the sake of brevity, the method has been explained in the description for
three power levels, i.e., the first power level, the second power level, and the next power level. The method is not limited to the three power level and it is evident to a person skilled in the art that it can be performed for a plurality of power levels.
[0034] Although the description herein is with reference to the smart meters and the
server in a smart metering environment, it will be understood that the present subject matter may be implemented for any nodes communicating in a communication network.
[0035] Fig. 2 illustrates details of the system 102, according to an embodiment of the
present subject matter. In said embodiment, the system 102 includes one or more processor(s) 202, a memory 206 coupled to the processor(s) 202, and interface(s) 204. The processor(s) 202 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor(s) 202 are configured to fetch and execute computer-readable instructions and data stored in the memory 206.
[0036] The interface(s) 204 may include a variety of software and hardware
interfaces, for example, interface for peripheral device(s), such as a keyboard, a mouse, an external memory, a printer, etc. Further, the interface(s) 204 may enable the system 102 to communicate over the network 106, and may include one or more ports for connecting the system 102 with other computing devices, such as web servers and external databases. The interface(s) 204 may facilitate multiple communications within a wide variety of protocols and networks, such as a network, including wired networks, e.g., LAN, cable, etc., and wireless networks, e.g., WLAN, cellular, satellite, etc.
[0037] The memory 206 may include any computer-readable medium known in the art
including, for example, volatile memory, such as static random access memory (SRAM) and dynamic random access memory (DRAM), and/or non-volatile memory, such as read only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes. The memory 206 further includes modules 208 and data 210.

[0038] The modules 208 include routines, programs, objects, components, data
structures, etc., which perform particular tasks or implement particular abstract data types. The modules 208 further include a test module 212, the analysis module 110, and other module(s) 214. The other module(s) 214 may include programs or coded instructions that supplement applications and functions on the system 102, for example, programs in the operating system.
[0039] The data 210, amongst other things, serves as a repository for storing data
processed, received, and generated by one or more of the modules 208. The data 210 includes test data 216, consumption data 218, and other data 220. The other data 220 may include data generated as a result of the execution of one or more modules in the other module(s) 214.
[0040] As previously described, the system 102 may be capable of exchanging data
packets with other devices, such as the server 104 connected- The system 102 is configured to optimize the RF output power required for the communication of data packets. In one implementation, the test module 212 may be configured to transmit the predefined number of test packets to the server 104 determine the optimum power level. Initially, the test module 212 may set the power level of the RF power at the lowest power level. Further, the test module 212 may transmit the predefined number of test packets to the server 104 at the lowest power level. As previously discussed, the server 104 may be configured to receive and process the information received from the test module 212 in the form of data packets, such as the test packets.
[0041] On receiving one or more of the test packets, the server 104 may send one or
more acknowledgements in response to the test packets teceived by the server 104. For instance, in case the server 104 receives all the test packets transmitted by the test module 212, the server 104 may transmit an acknowledgement corresponding to each of the test packets. However, in case the server 104 receives only few, say five, of the test packets transmitted by the test module 212, the server 104 may transmit only five acknowledgements corresponding to the received test packets. On receiving the acknowledgements from the server 104, the test module 212 may determine the number of acknowledgements received from the server 104. Further, the test module 212 may save the predefined number of packets and the acknowledgments in the test data 216. However, in case the test module 212 does not

receive any acknowledgement within a predetermined time period, the test module 212 may assume that none of the test packets has been successfully transmitted to the server 104. The test module 212 in such a case may increase the power level from lowest power level to a next power level by one level. The test module 212 may thus increase the power level until either at least one acknowledgment is received by the test module 212 or a highest power level of the system 102 is reached. The highest power level may be defined as the power level beyond which the RF power may not be increased. In case no acknowledgement is received even, at the highest power level of the system 102 the test module 212 may generate an error message stating that the server 104 is not within the range of the communication.
[0042] Further, if at a particular power level at least one acknowledgment is received,
the test module 212 may ascertain the particular power level as the first power level. Based on the acknowledgments received at the first power level, the test module 212 may be configured to determine the number of lost test packets from the predefined number of test packets during the communication. The lost test packets may be defined as the test packets lost in the transmission to the server 104, i.e., the test packets for which no acknowledgment is received, by the test module 212. For example, let us assume that 50 test packets are transmitted to the server 104. Some test packets may be lost in the transmission and the server 104 may receive only 30 test packets. Now, the server 104 may send the acknowledgment for the 30 test packets received. Further, the system 104 based on the acknowledgments may determine the 20 test packets lost in the transmission. In case the test module 212 receives acknowledgement for each of the predefined number of test packets, i.e., the number of lost test packets is zero, the test module 212 may determine the first level as the optimum power level.
[0043] However, in case the number of lost test packets is greater than zero, the test
module 212 may identify the first set of lost test packets. The test module 212 may further determine estimated power required for transmitting the first set of lost test packets at the first power level based on RF circuit parameters. The RF circuit parameters may specify the range of power required for transmitting number of test packets to the server (104). Further, the test module 212 may determine the first total power consumed in successful transmission of the test packets at the first power level. As previously described, the first total power may include the estimated power and the power consumed in transmitting the test packets at the first power

level. For example, the test module 212 may estimate that each packet requires 10 milliwatt (mW) for successful transmission. If the test module transmits 10 packets and 2 packets are lost in the communication, the test module may estimate that extra 20 mW may be needed for the transmission of the 2 lost packets. The test module may estimate that total power of 120 mW may be consumed in successful transmission of the 10 test packets. In another implementation, the test module 212 may be configured to increase the power to a second power level, such as the next power level. The test module 212 may subsequently transmit the predefined number of test packets to the server 104 at the second power level. Further, the test module 212 may identify the second set of lost test packets during the transmission of the predefined number of test packets at the second power level. For instance, the test module 212 may determine whether an acknowledgment corresponding to each of the test packet - transmitted to the server 104 at the second power level is received. The test packets for which the acknowledgment is not received may be considered as the second set of lost test packets. In case no test packet from among the predefined number of test packets is lost, the test module 212 may ascertain the second power level as the optimum power level. However, in case even a single lost test packet is identified, the test module 212 may determine the estimated power required for retransmitting the second set of lost test packets at the second power level.
[0044] Further, the test module 212 may determine the second total power consumed
in successful transmission of the test packets at the second power level. As previously described, the second total power may include power consumed in transmitting the test packets at the second power level and the estimated power required for transmitting the second set of lost test packets. In one implementation, the test module 212 may store the first total power and the second total power in the consumption data 218.
[0045] Upon determining the first total power and the second total power, the analysis
module 110 may determine the optimum power level for transmitting the predefined number of test packets. In one implementation, the analysis module 110 may be configured to compare the first total power and the second total power to determine the optimum power level. For the purpose, the analysis module 110 may access the consumption data 218 and obtain the first total power and the second total power. Based on the comparison, the analysis module 110 may determine whether the first total power is less than the second total power. If

the first total power is less than the second total power, the analysis module 110 may ascertain the first power level as the optimum power level. On the other hand, if the second total power is less than the first total power, the test module 212 may increase the second power level to the next power level. The test module 212 may further determine the next total power required for the successful transmission of the test packets and compare the next total power with the second total power. The test module 212 may thus keep on repeating the above process of increasing the power level and determining the total power consumed in successful transmission until either the power required at the lower power level, say the second power level, is less than the power required at the higher power level, say the next power level, or a power level is reached at which no test packet is lost. For example, in case the analysis module 110 finds that total power consumed at the fourth power is less than the total power consumed at the third power level, the test module 212 may increase the power level to a fifth power level. The test module 212 may compare the total power consumed in successful transmission of test packets at both the power levels. In case, the analysis module 110 identifies that a maximum power level is reached and the total power consumed at the maximum power level is less than the total power at the previous power level, the analysis module 110 may ascertain the maximum power level as the optimum power level.
[0046] Determining the optimum power level based on the comparison thus helps the
analysis module 110 in saving the extra power required for the communication of the data packets. Thus, the life of the battery installed in the system 102 may increase enabling the system 102 to operate for a longer period with same amount of power.
[0047] Figs. 3(a) and 3(b) illustrate a method 300 of optimizing power, such as RF
power consumed in communication between two nodes, in accordance with an embodiment of the present subject matter. The method 300 may be implemented in computing device, such as the system 102. Further, the method may be implemented in any networking environment, such as a smart metering environment having two nodes, such as a smart meter and a data collector communicating with each other. The method may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, etc., that perform particular functions or implement particular abstract data types. The method may also be practiced in a distributed computing environment where functions

are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer executable instructions may be located in both local and remote computer storage media, including memory storage devices.
[0048] The order in which the method is described is not intended to be construed as a
limitation, and any number of the described method blocks can be combined in any order to implement the method, or an alternative method. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.
[0049] At block 302, a predefined number of test packets are transmitted at a first
power level. The test packets may be transmitted from a first node to a second node. In one implementation, the first power level may be defined as a minimum power level at which at least one of the predefined number of test packets may reach the second node, such as the server 104. In one implementation, the system 102 may be configured to transmit the predefined number of test packets to the server 104 at the first power level.
[0050] At block 304, a determination is made to ascertain whether an
acknowledgment corresponding to each of the test packet is received. For example, the system 102 may determine whether the server 104 has sent acknowledgements corresponding to each of the test packets transmitted by the system 102. In case, the acknowledgment corresponding to each of the test packets transmitted to the second node at the first power level, is received, it ascertains the first power level as the optimum power level at block 306, as illustrated in fig. 3(b). If it is determined that acknowledgement corresponding to each of the test packets is not received, which is the 'No' path from the block 304, the method moves to block 308.
[0051] At block 308, a first set of lost test packets is determined from among the
predefined number of test packets based on the acknowledgments received. In one implementation, the first set of lost test packets may be defined as the test packets for which no acknowledgment is received, i.e., the test packets that fail to reach the server 104. In one implementation, the system 102 may identify the first set of lost test packets from the predefined number of the test packets based on the acknowledgment received.

[0052] At block 310, a first total power consumed in successfully transmitting the
predefined number of test packets is determined. The first total power may include the power consumed in transmitting the predefined number of test packets at the first power level and estimated power required for transmitting the first set of lost test packets. In one implementation, the estimated power may be determined on the basis of RF circuit parameters. For example, if one test packet requires 10 milliwatt (mW) for transmission then 10 packets are transmitted at the power of 100 mW. In such a case if two packets are lost in the transmission then it may be estimated that power of 20 mW may be required for the transmission of the two lost packets. The first total power m^y thus be determined as 120 mW power. In one implementation, the system 102 may determine the first total power required for successful transmission of the predefined number of test packets to the server 104 at the first power level.
[0053] At block 312, the predefined number of test packets is transmitted at a second
power level. Initially, the powes may be increased from the first powar level to a second power level greater than the first power level. For example, the system 102 may increase the ' first power level to a second power level and transmit the predefined number of test packets at the second power level.
[0054] At block 314, a determination is made to ascertain whether an
acknowledgment corresponding to each of the test packet is received. For example, the system 102 may determine whether the server 104 has sent acknowledgements corresponding to each of the test packets transmitted by the system 102 at the second power level. In case, the acknowledgment corresponding to each of the test packets transmitted to the second node at the second power level, is received, it ascertains the second power level as the optimum power level at block 316, as illustrated in fig. 3(b). If it is determined that acknowledgement corresponding to each of the test packets is not received, which is the 'No' path from the block 314, the method moves to block 318.
[0055] At block 318, a second set of lost test packets is identified from among the
predefined number of test packets based on the acknowledgments received. In one implementation, the second set of lost test packets may be defined as the test packets for which no acknowledgment is received at the second power level, i.e., the test packets that fail

to reach the server 104. In one implementation, the system 102 may identify the second set of lost test packets from the predefined number of the test packets based on the acknowledgment received.
[0056] At block 320, a second total power consumed in successfully transmitting the
predefined number of test packets at the second power level is determined. The second total power may include power consumed in transmitting the predefined number of test packets at the second power level and estimated power consumed for transmitting the second set of lost test packets. In one implementation, the system 102 may add the power consumed in transmitting the predefined number of test packets at the second power level and the estimated power consumed for transmitting the second set of lost test packets to determine the second power level.
[0057] At block 322, a determination is made to ascertain whether the second total
power level is less than the first total power. In case, the second total power is greater than the first total power, which is the 'No' path from the block 322 it ascertains the first power level as the optimum power level at the block 306. If it is determined that the second total power is less than the first total power, which is the 'Yes' path from the block 322, the method moves to block 324.
[0058] At block 324, a determination is made to ascertain whether the second power
level is equal to a maximum power level. The maximum power level may be defined as the power level beyond which power of an RF circuitry cannot be increased. In case, the second power level is equal to the maximum power level, which is the 'Yes' path from the block 324 it ascertains the second power level as the optimum power level at the block 316. If it is determined that the second total power is not the maximum power level, which is the "No' path from the block 324, the method moves to block 326.
[0059] At block 326, next total power consumed in successfully transmitting the
predefined number of test packets at a next power level is determined. The next power level may be defined as a power level having power higher than the second power level. The next power level may thus be determined as a higher power level while the second power level may be determined as a lower power level. In one implementation, the system 102 may

determine total power required in successful transmission of test packets at the higher power level.
[0060] At block 328, the next total power may be compared with the second total
power. In one implementation, the system 102 may be configured to compare the next total power may be compared with the second total power to determine the optimum power level.
[0061] At block 330, an optimum power level is determined based on the comparison.
In one implementation, the power level at which minimum power is required for successful transmission of the predefined number of test packets may be determined as the optimum power level for transmitting data packets. For instance, on determining that the second total power is less than the next total power, the second power level may be determined as the optimum power level for transmitting data packets. However, on determining, that the second total power is greater than the next total power, the process of increasing the power level to a higher power level and comparing the power levels at the higher power level and a lower power level may be repeated. The of increasing the power level to the higher levels and determining total power for the higher levels may be repeated until either the power required at the lower power level is less than the power required at the higher power level or a power level at which no test packet is lost is reached. The system 102 may thus be configured to calculate and compare the power consumed in successfully transmitting the predefined number of test packets at the various power levels, such as the first power level, the second power level, and next power level. Based on the comparison, the power level, from the various power levels, at which minimum power is consumed in successfully transmitting the predefined number of test packets is ascertained as the optimum power level by the system 102.
[0062] For the sake of brevity, the method has been explained in the description for
three power levels, i.e., the first power level, the second power level, and the next power level. The method is not limited to the three power level and it is evident to a person skilled in the art that it can be performed for a plurality of power levels.
[0063] The systems and methods of the present subject matter thus help in optimizing
RF power by analyzing transmission of predefined number of test packets at different power levels. Although embodiments for systems and methods of optimizing RF power have been

described in language specific to structural features and/or methods, it is to be understood that the invention is not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as exemplary implementations of RF power optimization in communication between two nodes.

I/We claim:
1. A method for radio frequency (RF) power optimization between two communicating
nodes, the method comprising:
determining a first total power consumed in successfully transmitting a predefined number of test packets at a first power level, wherein the first total power includes total power consumed in transmitting the predefined number of test packets and estimated power for transmitting a first set of lost test packets at the first power level;
determining a second total power consumed in successfully transmitting the predefined number of test packets at a second power level, wherein the second total power includes power consumed in transmitting the predefined number of test packets at the second power level and estimated power for transmitting a second set of lost test packets at the second power level;
comparing the first total power with the second total power; and
ascertaining the first power level as an optimum power level, for transmission of data packets between the two communicating nodes, upon determining the first total power to be less than the second total power based on the comparing.
2. The method as claimed in claim 1, wherein the ascertaining comprises:
determining, upon the second total power being less than the first total power based on the comparing, a next total power consumed at a next power level; and
comparing the next total power with the second total power to determine the
i optimum power level; and
ascertaining the second power level as the optimum power level, upon determining the second total power to be less than the next total power based on the comparing the next total power with the second total power
3. The method as claimed in claim 3, further comprises determining the next power level
as the optimum power level on receiving an acknowledgment corresponding to each of the
predefined number of test packets transmitted at the next power level.

4. The method as claimed in claim 1, wherein the determining the first total power
comprises:
transmitting, to a second node, the predefined number of test packets at the first power level;
identifying the first set of lost test packets from among the predefined number of test packets based at least on an acknowledgment received by a first node; and
determining the estimated power for retransmitting the first set of lost test packets at the first power level.
5. The method as claimed in claim 4, wherein the identifying comprises:
receiving one or more acknowledgements from the second node;
determining one or more test packets, from among the predefined number of test packets, corresponding to the one or more acknowledgments as transmitted packets, wherein remaining of the predefined number of test packets are ascertained as the first set of lost test packets.
6. The method as claimed in claim 1 further comprises generating an error message on unsuccessful transmission of the predefined number of test packets at a maximum power level, wherein the unsuccessful transmission occurs when no acknowledgment is received for at least one of the predefined number of test packets.
7. The method as claimed in claim 1 further comprises:
transmitting the predefined number of test packets at a lowest power level; wherein the lowest power level is minimum power required for transmission of the predefined number of test packets;
identifying whether at least one acknowledgment corresponding to the predefined number of test packets is received; and
ascertaining the lowest power level as the first power level based on the identifying, wherein the first power level is the power level at which the at least one acknowledgment is received.
8. A power optimization system (102) comprising:
a processor (202); and
a memory (206) coupled to the processor (202), the memory (206) comprising: a test module (212) configured to,

determine a first total power consumed in successfully transmitting a predefined number of test packets at a first power level, wherein the first total power includes total power consumed in transmitting the predefined number of test packets and estimated power for transmitting a first set of lost test packets at the first power level;
determine a second total power consumed in successfully transmitting the predefined number of test packets at a second power level, wherein the second total power includes power consumed in transmitting the predefined number of test packets at the second power level and estimated power for transmitting a second set of lost test packets at the second power level; and an analysis module (110) configured to,
compare the first total power with the second total power; and
ascertain an optimum power level for transmission of data packets between two communicating nodes based on the comparing.
9. The power optimization system (102) as claimed in claim 10, wherein the test module
(212) is further configured to,
transmit the predefined number of test packets at the first power level;
identify the first set of lost test packets from among the predefined number of test packets based at least on an acknowledgment received; and
determine the estimated power required for retransmitting the first set of lost test packets at the first power level.
10. The power optimization system (102) as claimed in claim 10, wherein the test module (212) is further configured to determine, for the second total power being less than the first total power, next total power consumed at a next power leveU
11. The power optimization system (102) as claimed in claim 10, wherein the analysis module (110) is further configured to ascertain the first power level as the optimum power level for the first total power being less than the second total power.
12. The power optimization system (102) as claimed in claim 10, wherein the analysis module (110) is further configured to ascertain the first power level as the optimum power

level upon receiving the acknowledgments for each of the predefined number of test packets at the first power level.
13. The power optimization system (102) as claimed in claim 10, wherein the analysis module (110) is further configured to ascertain the second power level as the optimum power level upon receiving the acknowledgments for each of the predefined number of test packets at the second power level.
14. The power optimization system (102) as claimed in claim 10, wherein the analysis module (110) is further configured to generate an error message when no acknowledgment is received at a maximum power level.
15. A computer-readable medium having embodied thereon a computer program for executing a method comprising:
determining a first total power consumed in successfully transmitting a predefined number of test packets at a first power level, wherein the first total power includes total power consumed in transmitting the predefined number of test packets and estimated power for transmitting a first set of lost test packets at the first power level;
determining a second total power consumed in successfully transmitting the predefined number of test packets at a second power level, wherein the second total power includes power consumed in transmitting the predefined number of test packets at the second power level and estimated power for transmitting a second set of lost test packets at the second power level;
comparing the first total power with the second total power; and
ascertaining the first power level as an optimum power level, for transmission of data packets between the two communicating nodes, upon determining the first total power to be less than the second total power based on the comparing.