Showing posts with label Battery. Show all posts
Showing posts with label Battery. Show all posts

Thursday 29 September 2022

Four Ways 5G Can Improve the Battery Life of User Equipment (UE)

We have looked at different approaches in this blog and the 3G4G website on reducing the power consumption (see related posts below). In a blog post some months back, Huawei highlighted how 5G can improve the battery life of UE. The blog post mentioned four approaches, we have looked at three of them on various blogs. 

The following is from the blog post:

RRC_INACTIVE State

A UE can access network services only if it establishes a radio resource control (RRC) connection with the base station. In legacy RATs, a UE is either in the RRC_CONNECTED state (it has an RRC connection) or the RRC_IDLE state (it does not have an RRC connection). However, transitioning from the RRC_IDLE state to the RRC_CONNECTED state takes a long time, so it cannot meet the low latency requirement of some 5G services. But a UE cannot just stay in the RRC_CONNECTED state because this will consume much more UE power.

To solve this problem, 5G introduces the RRC_INACTIVE state, where the RRC connection is released but the UE context is retained (called RRC Release with Suspend), so an RRC connection can be quickly resumed when needed. This way, a UE in the RRC_INACTIVE state can access low-latency services whenever needed but consume the same amount of power as it does in the RRC_IDLE state.

DRX + WUS

Discontinuous reception (DRX) enables a UE in the RRC_CONNECTED state to periodically, instead of constantly, monitor the physical downlink control channel (PDCCH) to save power. To meet the requirements of different UE services, both short and long DRX cycles can be configured for a UE. However, when to wake up is determined by the predefined cycle, so the UE might wake up unnecessarily when there is no data scheduled.

Is there a way for a UE to wake up only when it needs to? Wake-up Signal (WUS) proposed in Release 16 is the answer. This signal can be sent before the next On Duration period (during which the UE monitors the PDCCH) so that the UE wakes up only when it receives this signal from the network. Because the length of a WUS is shorter than the On Duration Timer, using WUS to wake up a UE saves more power than using only DRX.

BWP Adaptation

In theory, working on a larger bandwidth consumes more UE power. 5G provides large bandwidths, but it is unnecessary for a UE to always work on large bandwidth. For example, if you play online mobile games on a UE, only 10 MHz of bandwidth is needed for 87% of the data transmission time. As such, Bandwidth Part (BWP) is proposed in 5G to enable UEs to work on narrower bandwidths without sacrificing user experience.

BWP adaptation enables the base station to dynamically switch between BWPs based on the UE’s traffic volume. When the traffic volume is large, a UE can work on a wide BWP, and when the traffic volume is small, the UE can work on a narrow one. BWP switching can be performed based on the downlink control information (DCI) and RRC reconfiguration messages. This ensures that a UE always works on a bandwidth that supports the traffic volume but does not consume too much power.

Maximum MIMO Layers Reduction

According to 3GPP specifications, the number of receive and transmit antennas used by a UE cannot be fewer than the maximum number of MIMO layers in the downlink and uplink, respectively. For example, when a maximum of four downlink MIMO layers are configured for a UE, the UE must enable at least four receive antennas to receive data. Therefore, if the maximum number of MIMO layers can be reduced, the UE does not have to activate as many antennas, reducing power consumption.

This can be achieved in 5G because the number of MIMO layers can be re-configured based on assistance information from UEs. After receiving a request to reduce the number of MIMO layers from a UE, the base station configures fewer MIMO layers for the UE through an RRC reconfiguration message. In this way, the UE can deactivate some antennas to save power.

Power consumption in the networks and the devices is a real challenge. While the battery capacity and charging speeds are increasing, it is also important to find ways to optimise the signalling parameters, etc. One such approach can be seen in the tweet above regarding regarding T-Mobile in The Netherlands, selectively switching off a carrier in the night and switching it back when the cell starts loading or in the morning.

We will see lot more innovations and optimisations to dynamically update the technologies, parameters, optimisations to ensure power savings wherever possible.

Related Posts

Monday 14 December 2020

Huawei's Power Digitalization 2025 Summit


Back in October, Huawei held Better World Summit 2020 (a.k.a. "Win-Win Future" Global Online Summit). The theme of this online summit was "Power Digitalization 2025”. Experts and operators shared their ideas, vision and challenges. The following summary was shared by Huawei:

Today, how should global operators respond to opportunities and challenges brought by changes in the digital world, under the rapid development of digital technology and digital economy.

“Energy, as the foundation of the digital world, has become a key part and an important point of competitiveness in the digital economy.” Zhou Taoyuan, President of Digital Power Product Line, Huawei, pointed out that “The entire industry needs to attach greater importance to energy”

With the rapid development of emerging technologies such as 5G, cloud, AI, big data, and the IoT, a digital transformation has kicked off, opening the digital age where things are sensing, connected, and intelligent, "ubiquitous Connected, omnipresent intelligence" is becoming a reality. This has thrown the development of 5G and big data centers into the spotlight. But at the same time, the large-scale and rapid construction of 5G and data centers have brought huge challenges to energy infrastructure, such as increasing energy consumption, long construction periods, and high operation and maintenance costs.

“Pay-as-you-go model is becoming more popular in many countries, as data center owners are looking to a decrease their investment and turn their Capex into Opex. And that goes also for a number of other services as part of running and maintaining data center.” Lilia Severina,Global Major Accounts Director of Uptime Institute,talked about the insights into data center trends at the meeting. “Existing site energy facility cannot meet the power demands of 5G sites. There is a pressing need for reform and innovation in this area.Digitization,intelligent and integrated 5G power system enable faster, more affordable, and simpler 5G network deployment.” Liu Baochang, Deputy Director of Information Energy Department, China Mobile Group Design Institute Co., Ltd, expressed his opinion on the development trend and insights of site power in the 5G era.

Violaine Petit, Sales and Marketing VP of CRT Informatique, shared an interesting case about building data centers of CRT in a castle.“CRT did not just want to build something regular. We wanted to be different. We also wanted to invest in a meaningful project. Based on our business development and rejuvenating the castle, CRT successfully deployed two data centers in the castle to meet the dynamic digital development requirements of government and enterprise users. It can be said that the castle data center not only expands CRT's business boundary, but also can protects the country's cultural heritage, can be said to be two birds with one stone.”

Today, people lead a convenient life because of development of science and technology, while they also worry about the environment. How do we transit towards a net-zero carbon economy? Alberto Carrillo Pineda, Director of Science Based Targets, CDP, has his own view. “This includes changes in policies, technologies, economic structures and patterns of production and consumption, but the most important thing is that we change the way we live today. One of the changes is energy transition. Transitioning from fossil-based to clean and renewable energy and phasing out CO2 emissions in other parts of our economy.”

Zhou Taoyuan said, “Huawei integrates traditional power technologies and digital technologies to achieve power digitalization. In this way, we can use ‘Bit to manage Watt’, and provide simple, green, smart, and reliable digital power solutions to solve challenges faced by traditional power industry. ”

Fang Liangzhou, the Chief Marketing Officer of Huawei Digital Power Product Line, Huawei, said“Huawei uses a target network architecture to guide the planning, construction, O&M, and operation of digital power infrastructure, driving the rapid development of the digital economy. Concerning site power, Huawei proposes implementing 5G without increasing site power-related OPEX, and aims to reduce costs from three aspects as well as tapping into new sources. As for data centers, Huawei proposes a simple, green, smart, and reliable next-generation data center facility that uses the "four reconstructions" initiative to tackle issues such as long data center construction period, high energy consumption, and challenging O&M.”

In the future, Huawei will keep cooperating with global operators to face the challenges and seize the opportunities brought by the digital world. Huawei aims to inject green power into operators and help them grow business sustainably in the future. 

Surprisingly the only video I could find is on Periscope, embedded in the tweet above. You can jump on to the relevant sessions using the timestamps as follows

0:01:20 1. Opening Speech - Zhou Taoyuan, President of Digital Power Product Line, Huawei

0:07:14 2. Building a Net-zero Emissions Economy - Alberto Carrillo Pineda, Director of Science Based Targets, CDP

0:17:18 3. Trend and Insight of Site Power Facility in 5G era - Liu Baochang, Deputy Director of Information Energy Department, China Mobile Group Design Institute Co., Ltd

0:31:30 4. Perspective and Practice of Lithium Battery Application - José Pedro Nascimento, Network Director, Altice Portugal

0:40:10 5. Network Energy-Efficient Operation in EM Market - Li Yao, Deputy Director of NOC, China Mobile Pakistan

0:51:40 6. Trend and Insight of Data Center Facility - Lilia Severina, Global Major Accounts Director of Uptime Institute

1:10:30 7. Prefabricated Modular Data Center Case Sharing - Operator customers

1:16:20 8. Partnering To Power The Digital Datacenter - Violaine Petit, Sales and Marketing VP of CRT Informatique

1:25:10 9. New Era, New Power. PowerX 2025 Target Network - Dr. Fang Liangzhou, CMO of Digital Power Product Line, Huawei

Let me know what you think.

Friday 1 May 2020

The Futuristic Concept of 'Smart & Intelligent' Batteries


I did a presentation back in 2013 on the concept of smart batteries. Even though there has been a lot of progress in wireless charging since back then, it hasn't reached even close to the vision that I have. As a result, I converted it into a video to start a discussion on if and when this would be possible. The slides and video are embedded below and I welcome any discussion in comments below.






Sunday 10 September 2017

Smartphone Batteries Round-up: Technology, Charging & Recycling

Back in 2013, I spoke about Smart Batteries. Still waiting for someone to deliver on that. In the meantime I noticed that you can use an Android phone to charge another phone, via cable though. See the pic below:


You are probably all aware of the Samsung Galaxy Note 7 catching fires. In case you are interested in knowing the reasons, Guardian has a good summary here. You can also see the pic below that summarises the issue.


Lithium-ion batteries have always been criticized for its abilities to catch fire (see here and here) but researchers have been working on ways to reduce the risk of fire. There are some promising developments.


The electrochemical masterminds at Stanford University have created a lithium-ion battery with built-in flame suppression. When the battery reaches a critical temperature (160 degrees Celsius in this case), an integrated flame retardant is released, extinguishing any flames within 0.4 seconds. Importantly, the addition of an integrated flame retardant doesn't reduce the performance of the battery.

Researchers at the University of Maryland and the US Army Research Laboratory have developed a safe lithium-ion battery that uses a water-salt solution as its electrolyte. Lithium-ion batteries used in smartphones and other devices are typically non-aqueous, as they can reach higher energy levels. Aqueous lithium-ion batteries are safer as the water-based electrolytes are inflammable compared to the highly flammable organic solvents used in their non-aqueous counterparts. The scientists have created a special gel, which keeps water from reacting with graphite or lithium metal and setting off a dangerous chain reaction.


Bloomberg has a good report as to why we’re going to need more Lithium.

Starting about two years ago, fears of a lithium shortage almost tripled prices for the metal, to more than $20,000 a ton, in just 10 months. The cause was a spike in the market for electric vehicles, which were suddenly competing with laptops and smartphones for lithium ion batteries. Demand for the metal won’t slacken anytime soon—on the contrary, electric car production is expected to increase more than thirtyfold by 2030, according to Bloomberg New Energy Finance.

Even if the price of lithium soars 300 percent, battery pack costs would rise only by about 2 percent.

University of Washington researchers recently demonstrated the world's first battery-free cellphone, created with funding from the U.S. National Science Foundation (NSF) and a Google Faculty Research Award for mobile research.

The battery-free technology harvests energy from the signal received from the cellular base station (for reception) and the voice of the user (for transmission) using a technique called backscattering. Backscattering for battery-free operation is best known for its use in radio frequency identification (RFID) tags, typically utilized for applications such as locating products in a warehouse and keeping track of high-value equipment. An RFID base station (called a reader) "pings" the tag with an RF pulse, which allows the tag to harvest microwatts of energy from it—enough to return a backscattered RF signal modulated with the identity of the item.



Unfortunately, harvesting generates very little energy; so little, that you really need a new standard. For instance, Wi-Fi signals transmit continuously, but harvesting that energy constantly will only enable transmissions of about 10 feet today. Range will be the big challenge for making this technology successful.

So we wont be seeing them anytime soon unfortunately.

Recycling of materials is always a concern, especially now that the use of Lithium-ion is increasing. Financial Times (FT) recently did a good summary of all the companies trying to recycle Lithium, Cobalt, etc.

Mr Kochhar estimates over 11m tonnes of spent lithium-ion batteries will be discarded by 2030. The company is looking to process 5,000 tonnes a year to start with and eventually 250,000 tonnes — a similar amount to a processing plant for mined lithium, he said.

The battery industry currently uses 42 percent of global cobalt production, a critical metal for Lithium-ion cells. The remaining 58 percent is used in diverse industrial and military applications (super alloys, catalysts, magnets, pigments…) that rely exclusively on the material.

According to Wikipedia, The purpose of the Cobalt (Co) within the LIBs is to act as a sort of bridge for the lithium ions to travel on between the cathode (positive end of the battery) and the anode (the negative end). During the charging of the battery, the cobalt is oxidized from Coᶾ⁺ to Co⁴⁺. This means that the transition metal, cobalt, has lost an electron. During the discharge of the battery the cobalt is reduced from Co⁴⁺ to Coᶾ⁺. Reduction is the opposite of oxidation. It is the gaining of an electron and decreases the overall oxidation state of the compound. Oxidation and reduction reactions are usually coupled together in a series of reactions known as red-ox (reduction-oxidation) reactions. This chemistry was utilized by Sony in 1990 to produce lithium ion cells.

From Treehugger: An excellent investigative piece by the Washington Post called “The cobalt pipeline: From dangerous tunnels in Congo to consumers’ mobile tech” explores the source of this valuable mineral that everyone relies on, yet knows little about.
“Lithium-ion batteries were supposed to be different from the dirty, toxic technologies of the past. Lighter and packing more energy than conventional lead-acid batteries, these cobalt-rich batteries are seen as ‘green.’ They are essential to plans for one day moving beyond smog-belching gasoline engines. Already these batteries have defined the world’s tech devices.
“Smartphones would not fit in pockets without them. Laptops would not fit on laps. Electric vehicles would be impractical. In many ways, the current Silicon Valley gold rush — from mobile devices to driverless cars — is built on the power of lithium-ion batteries.”
What The Post found is an industry that’s heavily reliant on ‘artisanal miners’ or creuseurs, as they’re called in French. These men do not work for industrial mining firms, but rather dig independently, anywhere they may find minerals, under roads and railways, in backyards, sometimes under their own homes. It is dangerous work that often results in injury, collapsed tunnels, and fires. The miners earn between $2 and $3 per day by selling their haul at a local minerals market.

There is a big potential for reducing waste and improving lives, hopefully we will see some developments on this front soon.

Sunday 7 May 2017

10 years battery life calculation for Cellular IoT

I made an attempt to place the different cellular and non-cellular LPWA technologies together in a picture in my last post here. Someone pointed out that these pictures above, from LoRa alliance whitepaper are even better and I agree.

Most IoT technologies lists their battery life as 10 years. There is an article in Medium rightly pointing out that in Verizon's LTE-M network, IoT devices battery may not last very long.

The problem is that 10 years battery life is headline figure and in real world its sometimes not that critical. It all depends on the application. For example this Iota Pet Tracker uses Bluetooth but only claims battery life of  "weeks". I guess ztrack based on LoRa would give similar results. I have to admit that non-cellular based technologies should have longer battery life but it all depends on applications and use cases. An IoT device in the car may not have to worry too much about power consumption. Similarly a fleet tracker that may have solar power or one that is expected to last more than the fleet duration, etc.


So coming back to the power consumption. Martin Sauter in his excellent Wireless Moves blog post, provided the calculation that I am copying below with some additions:

The calculation can be found in 3GPP TR 45.820, for NB-IoT in Chapter 7.3.6.4 on ‘Energy consumption evaluation’.

The battery capacity used for the evaluation was 5 Wh. That’s about half or even only a third of the battery capacity that is in a smartphone today. So yes, that is quite a small battery indeed. The chapter also contains an assumption on how much power the device draws in different states. In the ‘idle’ state the device is in most often, power consumption is assumed to be 0.015 mW.

How long would the battery be able to power the device if it were always in the idle state? The calculation is easy and you end up with 38 years. That doesn’t include battery self-discharge and I wondered how much that would be over 10 years. According to the Varta handbook of primary lithium cells, self-discharge of a non-rechargable lithium battery is less than 1% per year. So subtract roughly 4 years from that number.

Obviously, the device is not always in idle and when transmitting the device is assumed to use 500 mW of power. Yes, with this power consumption, the battery would not last 34 years but less than 10 hours. But we are talking about NB-IoT so the device doesn’t transmit for most of the time. The study looked at different transmission patterns. If 200 bytes are sent once every 2 hours, the device would run on that 5 Wh battery for 1.7 years. If the device only transmits 50 bytes once a day the battery would last 18.1 years.

So yes, the 10 years are quite feasible for devices that collect very little data and only transmit them once or twice a day.

The conclusions from the report clearly state:

The achievable battery life for a MS using the NB-CIoT solution for Cellular IoT has been estimated as a function of reporting frequency and coupling loss. 

It is important to note that these battery life estimates are achieved with a system design that has been intentionally constrained in two key respects:

  • The NB-CIoT solution has a frequency re-use assumption that is compatible with a stand-alone deployment in a minimum system bandwidth for the entire IoT network of just 200 kHz (FDD), plus guard bands if needed.
  • The NB-CIoT solution uses a MS transmit power of only +23 dBm (200 mW), resulting in a peak current requirement that is compatible with a wider range of battery technologies, whilst still achieving the 20 dB coverage extension objective.  

The key conclusions are as follows:

  • For all coupling losses (so up to 20 dB coverage extension compared with legacy GPRS), a 10 year battery life is achievable with a reporting interval of one day for both 50 bytes and 200 bytes application payloads.
  • For a coupling loss of 144 dB (so equal to the MCL for legacy GPRS), a 10 year battery life is achievable with a two hour reporting interval for both 50 bytes and 200 bytes application payloads. 
  • For a coupling loss of 154 dB, a 10 year battery life is achievable with a 2 hour reporting interval for a 50 byte application payload. 
  • For a coupling loss of 154 dB with 200 byte application payload, or a coupling loss of 164 dB with 50 or 200 byte application payload, a 10 year battery life is not achievable for a 2 hour reporting interval. This is a consequence of the transmit energy per data bit (integrated over the number of repetitions) that is required to overcome the coupling loss and so provide an adequate SNR at the receiver. 
  • Use of an integrated PA only has a small negative impact on battery life, based on the assumption of a 5% reduction in PA efficiency compared with an external PA.

Further improvements in battery life, especially for the case of high coupling loss, could be obtained if the common assumption that the downlink PSD will not exceed that of legacy GPRS was either relaxed to allow PSD boosting, or defined more precisely to allow adaptive power allocation with frequency hopping.

I will look at the technology aspects in a future post how 3GPP made enhancements in Rel-13 to reduce power consumption in CIoT.

Also have a look this GSMA whitepaper on 3GPP LPWA lists the applications requirements that are quite handy.

Sunday 1 March 2015

Thursday 2 October 2014

Envelope Tracking for improving PA efficiency of mobile devices

I am sure many people would have heard of ET (Envelope Tracking) by now. Its a technology that can help reduce the power consumption by our mobile devices. Less power consumption means longer battery life, especially with all these new features coming in the LTE-A devices.
As the slide says, there are already 12 phones launched with this technology, the most high profile being iPhone 6/6 Plus. Here is a brilliant presentation from Nujira on this topic:



For people who are interested in testing this feature may want to check this Rohde&Schwarz presentation here.

Friday 29 August 2014

Wireless Charging: A must-have technology with maturing standards


Wireless charging has been in news recently with the discovery that Apple has found a brilliant way to wireless charge iPhones, iPads and iWatches. While we continue to wait for the details of that one, I thought its worth providing a bit of round up from the LTE World Summit not so long back. A summary of market by IHS is embedded as follows:



Qi (pronounced Chee), probably the most well known standard, not just because its already available in devices like Google Nexus 5 phone and Nexus 7 tablet  but also because its 1.2 standard allows devices to be charged from some distance away. They had an excellent presentation outlining their progress and technology as follows:





Finally, any discussion on Wireless Charging wont be complete without the mention of other big player, Alliance For Wireless Power (A4WP). The above shows a comparison between different standards and the presentation from A4WP is as follows:




Finally, if you haven't seen our concept of futuristic 'Smart Batteries' (crossed 10K+ views) then check it out here.

Tuesday 8 January 2013

VoLTE, Battery Issues and Solutions


Sometime back we had news about how VoLTE is battery killer and how it would suck our 4G phones dry. Well, I agree. I am no fan of VoLTE and think that CSFB solution can suffice in mid-term. Having said that, there is a solution which would be soon available to sort this battery issue during VoLTE call. I had a post on this topic earlier titled SPS and TTI Bundling. I am not sure about exactly how much saving would occur if either of the features are implemented.

ST Ericsson has recently released a whitepaper on this topic that is embedded below. If you have more idea on this, please add it in comments.



Friday 3 September 2010

Wireless Power Consortium (WPC) launches Qi



The WPC has chosen the Qi logo as the international symbol of wireless charging compatibility. Qi—pronounced “chee”, meaning “vital energy” in Asian philosophy—represents an intangible flow of power. Qi is the sign of interoperability between power transmitters and power receivers. All Qi receivers will work with any Qi transmitter. Every electronic device bearing the Qi symbol can be charged on any charging pad or surface marked with the same Qi logo.


In a post last year I mentioned about the wireless chargers. There were few that were released but they are expensive and not sure about the reliability.

The following is from eWeek:

The Wireless Power Consortium (WPC) has launched version 1.0 of its specification for charging handsets and other devices wirelessly, to be marketed under the name “Qi”, and has certified initial products for Blackberry and iPhone devices.

The product announcements come a year after the consortium announced version .95 of the spec. The products, including chargers for iPhone and BlackBerry devices, are to be demonstrated at a WPC meeting later this month.

Qi is based on inductive power transmission, already used in products such as the Touchstone charging dock used by the Palm Pre and the charging station for the Wii gaming console remote control. Such chargers allow a device to charge when placed on a flat surface or in a sleeve or dock. They eliminate the need for the connection of a metal contact connection, such as is found in standard cordless phone chargers.

The consortium, which includes Samsung, Sanyo, Olympus, Philips and Texas Instruments, aims to standardise inductive power charging technology so that chargers can be used with any device bearing the Qi logo. The specification is suitable for devices using up to 5 Watts of power, which the WPC said should cover “the majority of handheld mobile devices”.

“Qi can now be integrated into products. All ingredients for growing the market are now on the table,” said WPC chair Menno Treffers, in a statement.

Initial Qi-certified products are to include a charging sleeve for the iPhone 3GS and 3G and a charger for the Blackberry Curve 8900, both to be launched by Energizer this autumn. Sanyo, ST-Ericsson, National Semiconductor and others said they are working on Qi products.

Prototypes are to be demonstrated at a WPC meeting in Eindhoven, Belgium, from 15 to 16 September. The WPC said it has now begun work on a wireless charging specification for devices requiring more power, including netbooks, laptops, tablet computers and power tools.

The consortium said it chose the brand Qi (pronounced “chee”) to refer to the concept of energy flow in traditional Chinese medicine, not the cult quiz show QI (for “quite interesting”) hosted by Stephen Fry on British TV.

The technology is less ambitious than the system demonstrated this summer by Witricity, which operates at a distance of a few metres, using resonance, which the company claims has green benefits through replacing disposable batteries


From ZDNet:

"It took us only 18 months to develop the Qi standard, and less than one month to see the first products certified. Qi is now the industry's choice for wireless power," said Menno Treffers, chairman of the WPC, in a statement.

Three sets of specifications — for interface definition, performance requirements and test procedure — were handed over to consortium members in July. The only standard released publicly as Qi 1.0 is the interface definition, with the others being restricted to consortium members. The WPC has grown from 27 members in July to over 55 members, including Nokia, LG, Research In Motion, Duracell, Energiser and Texas Instruments.

Wireless charging has great potential to make charging easier for consumers", said Petri Vuori, Nokia's director of mobile solutions research, in the WPC announcement statement. "For full user benefit, a standard ensuring cross-compatibility between different manufacturers' products is required. Qi low-power standard specification release 1.0 is a significant milestone into this direction."

The Qi standard uses inductive charging to transfer up to 5W of power between devices and chargers. There are already products on the market that support inductive charging, but these are tied to particular products, rather than being universal.

The WPC said that it now plans to begin work on a wireless power standard for medium power devices such as netbooks, laptops, tablet computers and power tools.

The group expects the technology to boost the market for wireless battery charging from 100,000 units to 100,000,000 units annually. "Qi can now be integrated into products. All ingredients for growing the market are now on the table." said Treffers.


You may also be interested in the video below:

Tuesday 26 January 2010

Mobile Phone Batteries: Past, Present and Future

Forty-five years ago, when, to most people at least, chips only ever came with fish, a man called Gordon Moore wrote a paper in which he said the number of transistors that could be squeezed on to an integrated circuit doubles about every two years. Three years later, Moore co-founded Intel, whose computer chips have, to this day, developed almost exactly at the dizzying pace he predicted. Today, an Intel microprocessor boasts more than a billion transistors packed so densely that you could fit two million of the things on the full-stop at the end of this sentence. What became known as Moore's Law has driven exponential growth in the digital revolution – the more transistors you can pack into a circuit, the faster and more powerful its chips can run while remaining cheap. But the batteries keeping those circuits pinging are not digital and still work according to basic principles developed more than 200 years ago.

In the 1780s, Italian physicist Luigi Galvani discovered that a dead frog's leg would spring to life when he applied two pieces of metal. Galvani had created a crude circuit and the phenomenon was taken up by his friend, the aristocrat professor, Alessandro Volta. His voltaic pile swapped frogs for brine-soaked paper and pieces of metal for a stack of alternating zinc and copper disks. Volta had created the world's first modern battery.

A battery remains, by its simplest definition, a device that turns stored chemical energy into electrical energy. A chemical reaction takes place within a series of cells with negative and positive electrodes separated by conductive electrolyte. When you hook up the battery, positively charged ions "swim" from the negative to the positive electrode, prompting negatively charged electrons to power the bulb of a torch or the screen of your iPhone. It's a chemical process and, up to a certain point, you can't shrink chemistry. Peter Bruce, a professor of chemistry at the University of St Andrews, says that while computer performance has effectively doubled every two years, the energy density in batteries has increased five times in about 100 years. "If you want to store more energy you really have to develop new materials and new concepts," he says. "It's not just making the same things smaller."

Bruce is among a host of scientists racing to get more out of the modern battery. He owes a debt not only to Volta but also to the man whose work in the 1970s gave us the modern rechargeable battery that powers nearly all our gadgets. Stan Whittingham, a British-born American chemist who studied at Oxford in the 1960s, was working at the research division of the oil giant, Exxon, when he realised that the excellent energy-storing properties of the element lithium made it an ideal material to be used in rechargeable batteries. "A lithium-ion battery holds about five times as much energy as a lead one," Whittingham says on the phone from Binghamton University in New York, where he's a professor of chemistry. "It got a lot of people excited because it was really a technology-changing idea. Without lithium-ion batteries, you wouldn't have your iPod or your mobile phone. They've given us so much but of course people want more and more."

Bruce is taking up that challenge with his "air-fuelled" rechargeable lithium battery. Put very simply, the Stair cell (St Andrews air cell) uses nothing more complicated than air as a reagent in a battery instead of costly chemicals. By freeing up space and exploiting one of the few elements that is free, Bruce's cells can squeeze more power into a smaller space at a reduced cost. "By using air in the cell we can get much higher energy storage up to a factor of 10," Bruce says. "That's exciting because it's difficult to improve the lithium ion battery beyond a factor of two."

A battery with 10 times the storage of the one powering your phone would see a return to the days of weekly phone charging. Meanwhile, other scientists are working to solve that other great problem of the modern battery – the time it takes to recharge. Gerbrand Ceder at the Massachusetts Institute of Technology (MIT) has been looking at improving the way the lithium ions themselves move through batteries – the faster they "swim", the more quickly they charge the battery. Ceder and his team manipulated the materials inside batteries to make the ions' passage smoother and watched as they travelled at incredible speeds. Ceder estimates that a prototype battery made using the process could be charged not in hours or even minutes but seconds. "If we could cut charging time from, say, two hours to one hour, you would probably still do it overnight," he says. "But if it's one minute, you would stand by and wait – it would be like filling your car or getting a cup of coffee."

Ceder has also worked with a team that has used genetically-engineered viruses to build the positively and negatively charged ends of a lithium-ion battery. The new batteries would be more flexible and efficient than existing technology but, like MIT's fast-charging battery and Bruce's Stair cell, they are very much on the laboratory drawing board.

It's a measure of both the greatness of the modern battery and the challenges faced by developers that, as Whittingham puts it (perhaps with a degree of pride): "For the next five years at least it's just lithium." In the meantime, manufacturers are racing to launch energy-efficient screens and hardware that place less demand on batteries. But with so much riding on the next big breakthrough, it's only a matter of time before we get batteries fit to power the next generation of gadgets and cars. For those of us increasingly shackled to our phone chargers, that time can't come soon enough.


Tuesday 24 November 2009

Wireless Phone chargers coming in time for Christmas


We have talked about WiTricity and Nokia's self-recharging phones but they seem to be a bit far away.


PowerPad, made by the British gadget firm, Gear4, goes on sale next month and is among a new wave of devices sweeping us towards this unplugged utopia. A protective sleeve slips over an iPhone, slotting into its connecter socket. When the encased phone is placed on a mains-connected pad on, say, a desk or bedside table, electricity makes the jump. American outfits PowerMat and WildCharge make similar devices. Meanwhile, the Palm Pre smartphone has its own "Touchstone" charger and Dell's Latitude Z is the first wireless laptop.

"Wireless electricity is something we used to talk about years ago almost as a bit of a joke when we made predictions about the future," says Michael Brook, editor of the gadget magazine, T3. "To a lot of people it sounds insane that you could even do it – like some kind of witchcraft – but we're seeing a lot of interest in the first wireless chargers. It's going to take off in a big way." If not witchcraft, how does it work? Here's the science: Current from the mains is wired into a transmitter coil in the charging mat. This generates an electromagnetic field. A receiver coil in the phone's case takes the power from the magnetic field and converts it back into electricity that charges the device. By separating those coils, induction charging takes the 150-year-old principle used in the transformers found in most electric devices and splits it in half. No more tripping over laptop leads and their power bricks or diving under your desk to plug in your charger – just put your gadget on the mat and induction takes care of the rest.

But wireless induction, which, in a less-sophisticated form has charged electric toothbrush chargers and some medical implants for years, isn't perfect. Advances mean it's now viable for more demanding devices, but in the case of the PowerPad, it requires a case that adds bulk to what is already a hefty handset. Another drawback is the lack of compatibility – a phone with a PowerPad case will not charge on a PowerMat.

A growing group of electronics firms want to sdeal with the problem. The Wireless Power Consortium (WPC) includes Gear4 and the mobile phone giants, Nokia, Samsung and RIM, makers of the Blackberry. "These companies think there won't be a mass market for wireless charging unless there is a standard," says Menno Treffers, chairman of the consortium's steering group and a director at Philips.

Learning their lesson from the hopeless incompatibility of wired chargers, supporters of WPC's Qi ("chi") standard will put universal coils in devices that will work without cumbersome cases. They'll also be compatible with any charging mat, whether it's on your desk or recessed in a table at Starbucks. Treffers expects the first Qi-compatible devices to hit shelves next year.

But there remains a major flaw in charging mats – their need for proximity. Separation of even a millimetre renders most mats useless. Take your laptop to your bedroom to watch a DVD and you'll need a second mat or a cable. For a truly wireless scenario, electricity must make a giant leap.

Marin Soljacic is a Croatia-born physics professor at Massachusetts Institute of Technology (MIT). In 2002, he got annoyed when his wife's mobile phone woke him up with beeping when its battery ran low. "Not only did I have to wake up to plug it in but had to find the charger in the dark," he says. "I thought, power is everywhere – sockets all over the house – yet it isn't close enough." Soljacic was sure there must be a way to bridge the gap. He wanted his wife's phone to charge while it was still in her handbag. Two years ago, after months of equation crunching and computer modelling, Soljacic literally had a light bulb moment when he flicked the switch of a 60-watt lamp. No big deal except that the electricity powering the light was travelling two metres through thin air.

Soljacic and his team at MIT have since formed a company called WiTricity. Last July, its chief executive, Eric Giler, came to Oxford to demonstrate a wireless television. In front of an amazed audience at a technology conference, he powered up a giant plasma screen TV that had no cables. Electricity sprung from a sleek unit on the floor to a receiver mounted on the back of the screen. Last month, Giler travelled to Japan to show off a wirelessly-charged electric car. "Every time I show people they're blown away," Giler says. "When you see it up close it does appear almost magical."

Soljacic's magic takes the split-transformer model that powers charging mats and adds a key ingredient to make electricity fly. It's called resonance, the phenomenon that means a singer who matches the acoustic frequency of a wine glass can shatter it. Soljacic knew that two resonant objects of the same resonant frequency tend to exchange energy efficiently – imagine a tuning fork causing a nearby fork with the same frequency to chime sympathetically. His breakthrough was to work out a way to use resonance in magnetic form to transfer not sound but electricity. He explains: "By coupling the magnetic field that surrounds a resonant coil to another coil resonating at the same frequency, we can make the electricity hop from one to the other."

WiTricity's strongly coupled magnetic resonance means cars, TVs, free-standing lamps, and computers – anything that requires electricity – can be powered or charged from a central source in the ceiling or under the floor. And it's all totally safe. "The fields that we are generating in are about the same as the earth's magnetic field," Giler says. "We live in a magnetic field."

Giler and his team are in talks with big-name electronics manufacturers, including many of those who are putting their names to the Qi standard for charging mats. Giler says proximity charging is "first-generation stuff; by the end of next year you'll start seeing devices with WiTricity components built in". If he is right, homes and offices could soon be fully wireless. "It's a fundamental breakthrough in science and a game changer for the industry," he says. "Cut the cords and the world's going to change."

Interesting Video:




Saturday 15 August 2009

Kenya gets Solar Charged Phones



Kenya is home to at least 17 million mobile-phone customers, but only one million have regular access to electricity, making it difficult to recharge a mobile phone.


But the first solar-powered handset could change Kenya's telecommunication industry.

Monday 15 June 2009

Nokia developing self-recharging phone


Standby mode is often accused of being the scourge of the planet, insidiously draining resources while offering little benefit other than a small red light and extra convenience for couch potatos. But now Nokia reckons a mobile phone that is always left in standby mode could be just what the environment needs.

A new prototype charging system from the company is able to power itself on nothing more than ambient radiowaves – the weak TV, radio and mobile phone signals that permanently surround us. The power harvested is small but it is almost enough to power a mobile in standby mode indefinitely without ever needing to plug it into the mains, according to Markku Rouvala, one of the researchers who developed the device at the Nokia Research Centre in Cambridge, UK.

This may sound too good to be true but Oyster cards used by London commuters perform a similar trick, powering themselves from radiowaves emitted by the reader devices as they are swiped. And similarly old crystal radio sets and more recently modern radio frequency identification (RFID) tags, increasingly used in shipping and as antitheft devices, are powered purely by radiowaves.

The difference with Nokia's prototype is that instead of harvesting tiny amounts of power (a few microwatts) from dedicated transmitters, Nokia claims it is able to scavenge relatively large amounts of power — around a thousand times as much — from signals coming from miles away. Individually the energy available in each of these signals is miniscule. But by harvesting radiowaves across a wide range of frequencies it all adds up, said Rouvala.

Such wireless transfer of energy was first demonstrated by Nikola Tesla in 1893, who was so taken with the idea he attempted to build an intercontinental transmission tower to send power wirelessly across the Atlantic. Nokia's device is somewhat less ambitious and is made possible thanks to a wide-band antenna and two very simple circuits. The antenna and the receiver circuit are designed to pick up a wide range of frequencies — from 500 megahertz to 10 gigahertz — and convert the electromagnetic waves into an electrical current, while the second circuit is designed to feed this current to the battery to recharge it.

The trick here is to ensure that these circuits use less power than is being received, said Rouvala. So far they have been able to harvest up to 5 milliwatts. Their short-term goal is to get in excess of 20 milliwatts, enough power to keep a phone in standby mode indefinitely without having to recharge it. But this would not be enough to actually use the phone to make or receive a call, he says. So ultimately the hope is to be able to get as much as 50 milliwatts which would be sufficient to slowly recharge the battery.
would be a remarkable achievement. . "Radio frequency power falls off exponentially with distance," he says. Earlier this year researchers at Intel and the University of Washington, in Seattle, showed that they could power a small sensor using a TV signal 4.1 kilometres away.

Wireless charging is not intended as a sole energy source, but rather to be used in conjunction with other energy harvesting technologies, such as handset casings embedded with solar cell materials. According to Technology Review magazine, the phone could be on the market in three to five years.

Sunday 14 September 2008

Longer battery life for Notebooks

In the past decade the no of users switching notebooks has dramatically increased. Not only are the business personal, normal users accessing computer at home now preferring notebooks. The reason is quire simple as notebook/laptop provides mobility within the premises especially with wireless technology is now getting better.

The only limitation with the notebooks is its battery life. After using laptop for a while we do have to plug it back into the mains to charge it. Industry fully recognizes this limitation and hence the battle to create the notebook with the longer battery life is stepping up as every day passes by.

Dell recently announced new Latitude E6400 notebook with up to 19 hours of battery life. I am sure though the increase in battery life comes at the expense of extra weight. This increase in the battery life is due to the introduction of a new technology called a “slice,” which uses lithium-ion prismatic cell technology to extend the battery but it also added nearly 2 pounds of weight to the notebook.

On Sept. 8, HP announced that the company’s engineers had pushed the limits of battery life to the 24-hour mark with the EliteBook 6930p. So Hewlett-Packard has unveiled its own contender in response to Dell's announcement, where a new set of features for its HP EliteBook 6930p will push the battery life up to 24 hours. With a monster 12-cell lithium ion battery pack, HP claims that its new EliteBook 6930p is able to achieve 24 hours of runtime. As I mentioned above, off course this adds an additional 1.8 pounds to the laptop, which weighs 4.7 pounds with a "standard" lithium ion battery. However, the version of the notebook with 24 hours of battery life will not be available until October.

These developments from the likes of HP and Dell are definitely encouraged by the Intel’s new hardware which makes it possible to achieve higher goals. That is why it doesn’t surprise me that the HP announcement coincided with the release of new solid-state SATA (Serial ATA) drives from Intel, which are some of the key components to the notebook’s long battery life.

Since SSDs (solid state drives) use NAND flash memory and have no moving parts, these components reduce the laptops' overall power consumption.

As I mentioned above, the current business climate requires increased mobility and larger battery life for the notebooks. PC vendors such as Dell and HP are trying to target a new class of notebooks to enterprise road warriors who want to push the limits of mobility and who travel on airplanes for a good portion of the day or make several stops with customers across the span of several days. While 24- and 19-hour-battery life thresholds might seem a bit excessive, these claims by HP and Dell help showcase the ability of these vendors to push current battery technology to its limits. Notebook companies like HP and Dell also allowing users to download specific BIOS and driver updates that allow them to manipulate the power-saving features further.

It must be noted that since everyone is used to stretching the limits of battery performance, the actual "standard" usage life remains to be seen. Still, it is undeniable that as sales of laptops continue to dominate in the area of personal computing, it is inevitable that manufacturers reach out to globetrotting enterprise road warriors seeking to push the edge of mobility.

Monday 12 May 2008

Conserving power on 4G Phones

While we can see that the technology in mobile phones have advanced significantly, its still lagging on the battery front and there is no 'Duracell' solution for phones yet.

There is a cambridge (UK) based company called Nujira that is working on doubling the battery life for 4G phones. Here is an extract from Electronics weeely:

Nujira originally designed its RF power modulation technology to increase the efficiency of 650W power amplifiers in 3G mobile basestations. It is now working on a lower power version which should reduce cost and improve power efficiency in next generation 3G LTE (long term evolution) mobile phones.

According to Haynes, the company’s technology, known as HAT (high accuracy tracking), could more than double the time between charges for next generation mobile phones.

After a period when handset battery life has steadily increased with more power efficient designs, the situation could be reversed with the next generation of 3G LTE multimedia handsets.

According to Haynes, there are as many as 14 frequency bands - ten FDD frequency bands and four different TDD frequency bands - defined in 3GPP that can be used for LTE, and it is likely that more bands will be added to this list such as 700MHz in the US.

As current power amplifiers (PAs) can only efficiently cover one or two bands a large number of amplifiers will be needed in a multi-band 4G handset. “Already 3G handsets can have as many as five power amplifiers,” said Haynes.

“So a cost effective wide-band RF power amplifier is a key enabling technology for the creation of 4G handsets and our technology will make it possible to replace five or six narrow-band PAs with just one or two wide-band power amplifiers,” said Haynes.

The technology has already been proven in the basestation market where Haynes said the company has contracts with 10 basestation OEMs. For basestations Nujira has designed a high efficiency, high power DC-DC converter module.

For the handset market, which is potentially much higher volume, Haynes said the company will look at an IP (intellectual property) approach which will see its technology designed into more integrated silicon designs.
Haynes also said the company was developing a version of the power modulator for use in DVB digital broadcast transmitters.

Haynes expects to have its IP-based power modulator for handsets on the market by Mobile World Congress next February.