- Buyers Guide
The weather in Spain in February can never be guaranteed, but those attending the 2010 GSMA Mobile World Congress at the Fira de Barcelona from 15 to 18 February were met by particularly cold and damp wintry conditions. However, for those frequenting the premier event for the mobile communications industry and one of the first major shows of the year, it was the business climate, growth forecasts and the outlook for technological innovation that took precedence.
The bare statistics are brighter with the GSMA reporting 49,000 visitors (including delegates, exhibitors, contractors and media) from 189 countries attending the four-day conference and exhibition. This compares favourably with the 47,000 visitors from 189 countries recorded in 2009, but falls short of the show’s peak in 2008 when 55,000 visitors passed through the doors.
Last year’s Mobile World Congress took place as the economic turndown began to take a grip and there seemed to be a general acceptance that an industry that had a tendency to indulge in hype and self-promotion needed a reality check whereby investment and targets for business growth and expansion needed to be more cautious and realistic. Undoubtedly, there has been a degree of reassessment and of taking stock.
However, by its very nature the mobile communications industry has an inherent enthusiasm and dynamism that cannot be curbed and that was embodied at the 2010 Congress. It is an event that looks to the future and thrives on innovation. It focuses on cutting-edge technology that will affect how individuals, businesses and even nations communicate, obtain information and interact, not only tomorrow but well into the future.
The MWC is targeted by companies large and small to launch new products, discuss the latest technologies and to do business. However, a feature of this year’s event was the decision by a number of significant companies to focus on hospitality and pre-arranged meetings with key customers and clients rather than taking exhibition space.
Even so, the number of exhibiting companies remained similar to the last two years at 1,300. Hall 8 continued to be the busiest, followed by Hall 1 and then Hall 2, with all seeing significant traffic.
For the second year there was a dedicated FemtoZone in Hall 2. As well as being a showcase for the latest products, a speaker programme offered an insight into the plans of operators and research on the business case for femtocells. New for 2010 was the App Planet, a focused event designed to bring together the many critical elements of the broad mobile application ecosystem together in one location, which was visited by more than 20,000 people.
Such numbers demonstrate the mobile community’s obsession with apps, along with connectivity and downloading large amounts of data any time, any place, anywhere. The irony is that while the search for the killer app won’t actually kill the industry it could seriously wound it as the demand for services is in danger of overloading the existing infrastructure.
The desire for apps and the popularity of devices, particularly bandwidth-hungry smartphones to deliver them is leading to a real capacity crunch and putting a strain on networks. Every aspect of mobile internet connectivity is being impacted by straining capacity, from the mobile device (with MIMO antennas, multi-band/mode PAs, switch modules, FEMS, etc.) to the tower (base station PA linearity, new remote radio head solutions, rugged cable solutions, etc.) to microwave backhaul.
The silver lining to this cloud of over capacity is that the RF and microwave industry is in a position to provide the technology to provide solutions. Numerous companies showcased such technology at the Congress. In particular, test and measurement vendors addressed opportunities at the phone level (compliance and protocol testing) and the network level (MIMO over-the-air (OTA) testing, channel/fading emulation, multiple UE emulation). Alongside the text and measurement introductions there were also new product launches in the field of semiconductor and chipsets, cables, backhaul equipment and adaptive antennas.
Technology on Show
Companies large and small, from all four corners of the globe, and spanning the complete spectrum of the mobile communications industry targeted MWC 2010 to make key product announcements. Those particularly active in the RF and microwave sector were the test and measurement, semiconductor and chipset, components, femtocell and backhaul equipment manufacturers. Read on for a selection of the new products that were showcased.
Test and Measurement
To speed up real-world testing of mobile handsets for LTE networks ahead of network deployment, Aeroflex introduced what the company claims to be the first one-box test system for cell phone signal fading simulation. Integrated within the 7100 Series digital radio test set, the new fading simulator option offers RF engineers an inexpensive and reliable baseband tool for signal fading profiling, which is a requirement for LTE certification.
The 7100 Series supports both RF parametric and protocol testing for LTE terminal devices and simulates a network from the physical layer to the core network IP infrastructure. Focused on the R&D market – from components to handsets – the A7100 Series is a comprehensive test system for LTE mobile devices incorporated into a small footprint, single bench-top instrument.
Aeroflex also showcased the TM500 Test Mobile, which is said to be the first to market to support multiple user equipment, or handset emulation in conjunction with measurements for the 3GPP W-CDMA Release 8 Dual Cell High-Speed Download Packet Access (DC-HSDPA) standard. The TM500 DC-HSDPA Multi-UE Test Mobile enables 3G infrastructure equipment manufacturers to perform rigorous load testing. It can test the performance of DC-HSDPA base stations under conditions of increasing user demand, speeding up the development of infrastructure equipment and its deployment in networks.
The TM500 also supports the ability to test a base station and network against a multiple handset configuration. It enables base station and core network designs to be load tested, stressed, and optimized to ensure that robust, flexible and high-performance products are delivered to network operators.
Very active, as always, in developing new products Agilent Technologies introduced a new line of system-level design and verification products for 3GPP LTE physical layer (PHY) design and now provides predictive products and algorithmic references for the SystemVue platform that are consistent with the LTE v.8.9.0 (December 2009) standard. The new line includes four products that accelerate 4G deployment for LTE system architects, baseband hardware designers, and RF equipment by bringing new levels of realism into the architecture and modelling stages.
They are: The W1715 MIMO Channel Builder, which is a simulation blockset for LTE architecture and receiver designers, based on the WINNER and WINNER-II fading algorithms; the W1716 Digital Pre-Distortion builder helps LTE system integrators, RF component designers and baseband architects quickly transition from 3G to 4G by creating baseband signal processing networks that improve the range of analogue power amplifiers and transceiver ICs, improve efficiency, and extend battery life; the W1910 LTE Baseband Verification Library reference blockset has been updated to LTE v.8.9.0 and now includes expanded PRACH and HARQ support; and the W1912 LTE Baseband Exploration Library, which is a C++ source code version of the W1910 has also been updated.
The company also demonstrated how new advanced measurement applications embedded in the N9030A PXA signal analyzer are used to test RF transmitters. The advanced measurement applications test a variety of signal standards in cellular communication and digital video. Signal standards include LTE-FDD, LTE-TDD, W-CDMA/HSPA/HSPA+, DVB-T/H and ISDB-T. For LTE FDD and TDD, the N9080A and N9082A applications enable one-button testing that simplifies the design, validation and manufacturing of base stations and user equipment in accordance with 3GPP standards (TS 36.141 and TS 36.521-1).
Agilent also introduced and demonstrated a phone solution extension for its LTE Drive Test portfolio that will expand the coverage monitoring capability of the company’s Drive Test Receiver to include comprehensive interactive LTE network-performance testing. New capabilities have also been added to the Signalling Analyzer Real Time (SART) for LTE. These enhancements allow wireless carriers and network equipment manufacturers to analyze an LTE-enabled tenfold plus increase in network traffic without sacrificing real-time-to-results.
Anritsu Corp. showed off the real-world applications of its test equipment in conjunction with three collaborative companies. First, the company demonstrated its LTE solutions, including the MT8820C Radio Communication Analyzer, a next generation One Box Tester, and TS36.521 RF conformance tests with the ME7873L LTE radio frequency conformance test system using Samsung’s LTE devices. Second, the company announced that its MD8480C Signalling Tester with Dual-Carrier HSPA Evolution support has been selected by Sierra Wireless to demonstrate performance of the Sierra Wireless AirCard® 312U mobile broadband modem. Third, Anritsu demonstrated LG Electronics’ LTE modem with its LTE signalling tester, which comprises the MD8430A and the Rapid Test Designer (RTD).
Other products of note were the MS2830A Spectrum Analyzer, which is an addition to the expandable MS269xA product line. It supports frequency ranges from 3.6 to 13.5 GHz, providing superior RF specifications for average noise level of –153 dBm (1 GHz, without preamplifier), third-order inter-modulation distortion of +15 dBm, and total level accuracy of ±0.3 dB (typical). Easily customized expandability from the minimum configuration to an all-in-one advanced TRx tester helps keep down costs.
Anritsu’s ME7873L LTE RF Conformance Test System is claimed to be the first to provide independently verified European Radio equipment and Telecommunications Terminal Equipment (R&TTE) RF test cases for Type Approval of LTE devices. It can also be freely configured to meet customers’ TRx, performance, and RRM requirements and can be upgraded from the ME7873F W-CDMA RF Conformance Test System. In addition to supporting R&TTE test items, the ME7873L already supports part of the 3GPP TS36.521-1/3 test items and will soon have approval for the GCF/PTCRB work items, facilitating early production rollout of GCF/PTCRB-approved LTE terminals.
Rohde & Schwarz unveiled an extensive package of new features for the R&S CMW500 wideband radio communication tester aimed at delivering maximum flexibility for the mobile radio industry. The unit can deliver RF tests in signalling mode for CDMA2000® (1xRTT and 1xEV-DO), WiMAX and GSM, and measurements for implementing a smooth handover between LTE and W-CDMA or LTE and CDMA2000.
More functionality has been added so that at the protocol layer, the tester can perform 2 x 2 MIMO tests for HSPA+. In addition, it is capable of testing various procedures defined for EDGE Evolution, specifically those involving latency reduction and analysis of the downlink dual carrier. The R&S CMW500 is also a powerful multitechnology platform for initial measurements analyzing the handover of data links between LTE FDD and W-CDMA or LTE FDD and CDMA2000 1xEV-DO.
Also highlighted was the R&S CMW270, which is a flexible communications tester that can handle applications well beyond classic cellular mobile radio. It is capable of handling WiMAX plus WLAN, Bluetooth®, GPS and various broadcasting standards and can be equipped with additional technologies to accommodate specific requirements. It is a preconfigured version of the R&S CMW500 multitechnology platform and can be upgraded to full functionality when the need arises.
Rohde & Schwarz has also enhanced its R&S CONTEST test software by adding end-to-end tests on mobile phones under real-world receive conditions. The software runs on the R&S CMW500 wideband radio communication tester and the R&S TS8980 RF test system. It enables network operators and manufacturers of mobile phones to perform automated measurements of data throughput and voice communications quality at cell boundaries or under fading influences.
Power Amplifiers and Platforms
Taking pride of place on the ANADIGICS Inc. Stand was the AWC6323 – the latest version of the company’s dual-band CDMA power amplifiers, which are designed for today’s most advanced CDMA handsets and data cards. For the first time, high performance directional couplers have been integrated into a dual band CDMA PA in the 3 by 5 by 1 (mm) footprint.
The AWC6323 is manufactured on advanced indium gallium phosphide (InGaP) BiFET™ MMIC technology, delivering high levels of reliability, temperature stability and ruggedness and offers three mode states to achieve high power added efficiencies at several power levels during the phone operation. The PA features a common output port for the directional couplers built inside the package. These couplers offer 20 dB directivity and 22 dB coupling factor. This feature helps eliminate the surface-mount couplers placed on the phone board.
ANADIGICS also introduced a new, feature-rich PA, the AWT6283R, designed to significantly boost the performance and efficiency of WiMAX transceivers. It is said to be the industry’s first PA to deliver high linear output power, exceptional efficiency, and consistent RF performance over the full 3.3 to 3.8 GHz WiMAX frequency band. Suitable for mobile applications, the AWT6283R includes a step attenuator, a power detector and a reference voltage regulator in a small, easy-to-use package.
Infineon Technologies announced the availability of XMM™6260, the latest platform in its 3G slim-modem family, which is optimized as a slim-modem for smart phone architectures coupled with an application processor or as a standalone solution for PC modems and data cards. This advanced HSPA+ platform is based on two new highly integrated devices: the X-GOLD™626 baseband processor and the SMARTi™UE2 RF transceiver. Together with the Infineon 3GPP Release 7 protocol stack, the XMM 6260 platform comprises a fully integrated HSPA+ system solution.
Also featured was the SMARTi UE2 – the latest generation multi-band HSPA+/EDGE/GPRS RF transceiver for mobile devices. Its digital architecture reduces the number of power amplifiers from five to one and integrates all LNAs and interstage filters. SMARTi UE2 supports Quad-Band EDGE and Six-Band HSPA+ for global roaming and best area and indoor coverage. It boosts data rates up to 28.8 Mbps in downlink and 11.5 Mbps in uplink at the highest signal quality with Rx Diversity and MIMO.
Infineon Technologies also launched the XMM™6181, which is a new entry-level smartphone platform for Android handsets addressing the high volume consumer segment and addressed the growing Dual-SIM market with the new XMM™2138 platform, supporting Dual-SIM operation.
Nujira demonstrated what the company claims to be the world’s most efficient and cost-effective RF power amplifier based on Coolteq.L silicon, which it announced at MWC. The company’s test results using the new silicon show that a handset PA with Coolteq.L is twice as efficient during HSUPA and LTE transmissions, and 1.5 times as efficient during W-CDMA transmissions, compared with the same PA without Coolteq. Also, the peak current requirement during transmit is significantly reduced, enabling current-limited applications such as USB dongles to transmit at the full rated power, enabling 4G mobile broadband users to benefit from higher data rates, greatest coverage, and longer battery life.
Coolteq.L can be used as a basis for a highly linear front-end covering all of the twenty-three different frequency bands defined by 3GPP for LTE and all of the operating modes (GSM, EDGE, WCDMA, HSUPA and LTE) at the full 20 MHz signal bandwidth, using only two PAs.
The company also demonstrated its collaboration with other leading players present at the Congress. Nujira and RFMD demonstrated an efficient broadband PA design for 4G base stations. Using just one RFG1M device with a Coolteq.h module, the RFMD Nujira RF front-end transmits over a 728 to 960 MHz band with over 50 percent efficiency, covering seven of the frequency bands defined for LTE by 3GPP.
Nujira and TriQuint Semiconductor have successfully integrated the new TriQuint TriPower™ PA with Coolteq.h envelope tracking power modulator technology to create an efficient 2.1 GHz PA for cellular base stations. The PA test fixture combines the Coolteq.h modulator with a Triquint TriPower TG2H214120 device. The fixture achieves 56 percent efficiency at the 2.1 GHz LTE bandwidth W-CDMA signals (6.5 dB PAR) and 52 percent with LTE signals (8.5 dB PAR).
To enable a new generation of global smartphones and mobile internet devices requiring three or more bands of 3G or 4G RFMD has introduced PowerSmart™ for multi-band cellular RF architectures. At the heart of each platform is a new RF Configurable Power Core™, which leverages industry-leading functional efficiency and delivers state-of-the-art processing of all known cellular communications modulation schemes, including GSM/GPRS, EDGE, EDGE Evolution, CDMA, 3G (TD-SCDMA or WCDMA/HSPA+) and 4G (LTE or WiMAX).
The RF Configurable Power Core incorporates all power amplification and RF power management functionality. The platforms also include all necessary switching and signal conditioning functionality in a compact reference design. PowerSmart™ is modulation scheme agnostic and can support four bands of GSM/GPRS or EDGE and up to five bands of TD-SCDMA, W-CDMA/HSPA+, LTE, WiMAX or CDMA.
Expanding its family of dual-band and quad-band GSM/GPRS transmit modules RFMD introduced three new products – the RF7170, RF7171, and RF7172, while four new products have been added to the portfolio of 3G transmit modules – the RF3230, RF3231, RF3232, and RF3171. They are designed to accelerate the implementation of 3G entry-level feature phones supporting one-to-two bands of W-CDMA and two-to-four bands of GSM/GPRS. Each new transmit module features a GSM/GPRS PA and an integrated PHEMT switch to support stringent 3G linearity requirements.
The company also announced that it has commenced high-volume production of its RF720x W-CDMA/HSPA+ power amplifiers. The RF720x product family comprises seven high performance PAs designed for smartphones and 3G devices implementing mode-specific, band-specific front-end architectures. The family accommodates all major W-CDMA/HSPA+ bands and band combinations and is optimized to mate with reference designs from Qualcomm as well as other leading open market 3G chipset suppliers.
Skyworks Solutions introduced several highly integrated multimode power amplifier modules (PAM) for next-generation smart phones and data cards requiring multiple W-CDMA bands. The SKY77601, SKY77604, SKY77605 and SKY77607 are multimode and multiband (MMMB) PAMs for next-generation HSPA 3G phones and data modules. The devices operate efficiently in quad band GPRS and EDGE, and support bands 1, 2, 5 and 8 for W-CDMA and HSUPA modulation. SKY77601 and SKY77604 have been designed for improved performance under mismatch conditions and have reduced current consumption over the entire power range to maximize handset talk and standby times.
The SKY77602 PAM is designed for integrated data modules that support up to five W-CDMA bands – 1, 2, 4, 5 and 8. It integrates the functionality of five discrete PAs into a single package. This is the first in a family of products that will be released throughout 2010 that are optimized for specific mobile data requirements such as fixed supply voltage, reduced output power, and significant improvements to heat dissipation.
Skyworks also introduced a family of antenna switch modules (ASM) for 2/3/4G handset and data card platforms using both GaAs as well as silicon on insulator (SOI) technologies. The SKY13362 is a single-pole ten-throw ASM with an integrated CMOS decoder and dual low pass harmonic filters. The SKY14152 is a low-cost, single-pole eight-throw ASM for use in multimode embedded data cards, while the SKY14153 is a low-cost, single-pole four-throw switch designed for W-CDMA and diversity switching applications that demand high linearity and low-insertion loss. The SKY14155 is a low cost, double-pole four-throw switch designed for broadband, 3/4G band switching applications which demand low insertion loss, high isolation, and high linearity and the SKY18106 is a single-pole eight-throw ASM designed for multimode, high power switching applications that demand low harmonics and insertion loss.
The company announced that its portfolio of LTE power amplifier and front-end modules is now supporting the M710 solution from ST-Ericsson. The portfolio includes LTE front-end modules for Bands 1, 4, 7 and 8 (the SKY77445, SKY77455, SKY77456 and SKY77458) for worldwide applications, and PAMs supporting LTE-FDD for North America (the SKY77449 and SKY77453).
Components and Systems
The key announcement from Lime Microsystems was the availability of the LMS6002D, a multi-band multi-standard RF transceiver IC designed for small cell base stations and femtocells, featuring integrated high performance dual ADC and DAC. This single chip transceiver solution delivers increased levels of integration over the company’s analogue version, the LMS6002. The highly frequency agile transceiver operates at user-selectable frequencies between 375 MHz and 4 GHz and is suitable for 3G, WiMAX, and LTE operation.
The RF transceiver IC can be digitally configured to operate in the full range of those 375 MHz and 4 GHz frequency bands, with 16 user-selectable bandwidths of up to 28 MHz. It can therefore transmit and receive data across all W-CDMA and CDMA bands, as well as those used or planned for WiMAX and LTE.
The LMS6002D features high performance dual 12-bit ADC and DAC blocks, which provide the necessary multiplexed parallel interface to all currently available baseband ICs on the market for femtocell applications. It is packaged in a 9 by 9mm 116-pin DQFN package, and is available alongside an evaluation platform and reference design.
NXP Semiconductors announced that its Convertisseur Grande Vitesse (CGV™) series of JESD204A-compliant data converters is now interoperable with Altera Corp.’s Stratix IV GX and Arria II GX FPGA families, and will also be interoperable in the future with the Cyclone IV GX FPGA family.
CGV designates NXP‘s compliant, superset implementation of the JEDEC JESD204A interface standard, with enhanced rate (4 Gbps typical), enhanced reach (100 cm typical), enhanced features (multiple DAC synchronization) and assured FPGA interoperability. These data converters are suitable for cellular base stations and other wireless communication infrastructure equipment, as well as medical, instrumentation and military/aerospace applications.
NXP offers ADC and DAC evaluation boards that include the Altera HSMC interface for easy connection to Altera FPGA evaluation boards, allowing rapid demonstration of device interoperability. Both company’s evaluation boards are available to qualified OEMs worldwide.
Among a wide range of RF and microwave components and equipment exhibited by SPINNER, the new broadband splitters and a 2.6 GHz LTE multiplexer were the highlights. The broadband splitters cover all mobile communication bands that are used worldwide, ranging from the LTE 700 MHz band up to the 3.8 GHz WiMAX band and their small size and light weight make them particularly suitable for in-building distributed antenna systems applications.
At the same time, the splitters’ salt water resistant aluminium housing minimizes corrosion risk, making them suitable for outdoor use, even in the harshest of conditions. High power handling enables the splitters to easily handle multi-operator system requirements and their outstanding IM performance protects the system integrity and safeguards operators from loosing call traffic capacity.
The new SPINNER 2.6 GHz LTE multiplexer is available for various operator configurations from 5 up to 15 MHz channel bandwidth. The high channel isolation together with the low insertion loss make this multiplexer an ideal solution for antenna and/or feeder sharing. It reduces capex for the operators and allows environmental friendly site installations. The stainless steel housing is protected according to IP 65 and a DC bypass enables the power supply of tower mounted amplifiers or other nearby active antenna equipment.
Femtocells and Mobile Backhaul
Continuous Computing, picoChip and Cavium Networks announced their collaboration to produce what is said to be the world’s first complete LTE femtocell reference design. Available immediately, this solution helps accelerate time to market for product developers, femtocell access point manufacturers, network equipment vendors and operators. The reference design is the industry’s first to include the LTE modem (PHY), RF and packet processors, protocol software, intelligent router functionality and a complete Evolved Packet Core (EPC) simulator.
picoChip also unveiled three new products that address the complete range of femtocell requirements via a single design platform. There are two new picoXcell system-on-chip devices and an integrated suite of HSPA+ femtocell access point (FAP) software to offer a complete family of system-level femtocell solutions.
The new PC313 and PC323 chips extend the picoXcell family of devices. They are complete single-chip HSPA+ femtocell SoCs for eight or 24 users respectively, and are scalable to accommodate more users. They are said to deliver a number of industry firsts, including 3GPP Release 8 features such as 42 Mbps downlink and 11 Mbps uplink data rates and are pin-compatible with the industry-standard PC302 and PC312 devices. Features include MIMO to enable high data rates, and receive diversity, a technology that is essential to achieve the higher real-world user counts required for enterprise and ‘greater femto’ applications.
The PC2200 FAP software provides all of the core components of a 3GPP standards-defined Home NodeB, enabling manufacturers to more easily develop femtocells. This software stack delivers all of the software modules required to realize a complete 3GPP Home NodeB. It consists of six components: the PC2209 RNC Stack; the PC2252 Network Synchronization module; the PC2256 Security module; the PC2257 Operations and Maintenance module; the PC2258 Self-Organizing Network module; and the PC2259 Radio Resource Manager module.
NEC Corp. announced its Intelligent Converged Platform for mobile backhaul, which comprises the evolution of the company's mobile backhaul solutions and services to plan, build and operate next-generation mobile broadband for mobile operators.
The move follows NEC's strategic vision for the network transformation of mobile backhaul to help operators meet the challenges of next-generation mobile broadband performance demands and cloud carrier services. The platform is supported by a strong suite of professional services and high-quality engineering and is compatible with the company’s PASOLINK™ microwave mobile backhaul portfolio.
At the core of the platform is the Converged Packet Node, a modular network element that integrates a comprehensive set of transport and transmission features, resulting in reduced costs and long investment lifetime. With NEC's Intelligent Service Networking facility the platform will deliver an integrated package of network management software tools for auto-provisioning and end-to-end service management for quick time-to-revenue and low maintenance costs. Also, new control plane technologies will allow multi-policy network sharing.
In order to meet the early deployment of LTE, NEC will launch the first in a series of its Intelligent Converged Platform solutions later in 2010.
The RADWIN 2000 PDH is claimed to be the industry’s first sub 6 GHz microwave PDH System offering up to 16 x E1s/T1s+ Ethernet. A carrier-class solution, the system is specially designed to meet carriers’ cellular backhaul needs. It is the latest addition to the RADWIN 2000 product portfolio and all products incorporate advanced technologies such as MIMO, OFDM and Diversity together with unique proprietary protocols to ensure robustness and resiliency in the sub 6 GHz bands.
Providing a flexible combination of native TDM and Ethernet, RADWIN 2000 PDH comes with 1+1 Monitored Hot Standby support and built-in Spectrum View for locating the cleanest channel for operation. It is able to operate in challenging urban and rural environments, including non-line-of-sight scenarios, interference-ridden environments and extreme temperatures.
Also, newly released is the RADWIN 2000 C-Series of high capacity radios optimized for backhaul. The series delivers 100 Mbps asymmetric throughput and provides up to 16 E1s/T1s + Ethernet on one platform at ranges of up to 120 km. It offers Adaptive Asymmetric capacity whereby bandwidth is automatically allocated between uplink and downlink based on traffic loads and air-interface conditions.
The RADWIN 2000 C-Series incorporates advanced technologies such as MIMO, OFDM and Diversity. The system is simple to install and maintain and future-proof systems support 100 Mbps in the first release, and will support 200 Mbps net aggregate throughput in Q2 of 2010 via a free software upgrade.