Limo Foundation: Toward a Common Linux-Based Mobile Platform

Linux OS Mobile Terminal Platform Common Platform

LiMo Foundation: Toward a Common Linux-based Mobile Platform

LiMo Foundation was launched in January 2007 with the aim of creating the Mitsuaki Morita, Yuichi Ichikawa, world’s first globally competitive Linux®*1-based platform for mobile terminals. Kazuaki Terunuma This article describes efforts undertaken by the LiMo Foundation to develop and Hyunsuk Seung this platform.

NTT DoCoMo and five other mobile fees. Furthermore, founder members— 1. Introduction operators and mobile terminal manu- NTT DoCoMo, Motorola, Inc., NEC Functions equipped on mobile ter- facturers launched the “LiMo Founda- Corporation, Panasonic Mobile Com- minals are becoming increasingly tion” in January 2007. The LiMo munications Co., Ltd., Samsung Elec- advanced every year. To provide users Foundation aims to create the world’s tronics Co., Ltd., and Vodafone Group— with services that are compelling and first Linux-based global platform for aim to create a Linux platform for unique, innovative new software is mobile terminals to overcome the mobile terminals that is competitive needed these days to implement func- above challenge. compared to other platforms, construct tions such as music and video play- This article describes an overview an ecosystem essential for the expan- back, display of up-to-date information of the LiMo Foundation, its software sion of the platform over the medium via captions flowing across a standby architecture, the platform it provides, and long term, and enhance consumer screen, security functions for mis- and the platform’s relationship with experiences across a wide range of placed or lost mobile terminals, etc. Mobile-phone Oriented Application users. The idea here is to expand the This trend is not limited to Japan—it is Platform (Linux) (MOAP (L)). adoption of Linux in the mobile phone also happening in the global market. industry through contribution-based But software for satisfying users’ need 2. LiMo Foundation Overview development efforts of member com- for diverse and high-performance ser- 2.1 Aims and Objectives of the panies. vices are becoming more complicated LiMo Foundation and sophisticated, and the cost of soft- The Foundation aims to enable the 2.2 Benefits of Participation ware is rising as a result. Finding ways provision of attractive services to users Linux OS is distributed under an of reducing this cost burden has for mobile operators and mobile termi- open-source license that provides the become a common challenge among nal manufacturers to shorten develop- development community with three mobile operators and mobile terminal ment time and time-to-market of key features: (a) transparency—anyone manufacturers. mobile terminals and reduce the price may reference the OS source code, (b) Against this background, of mobile terminals by reducing license innovativeness—OS functions on

*1 Linux®: A registered trademark or trademark of Linus Torvalds in Japan and other coun- tries.

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servers and personal computers can be use of a common platform tion and the activities of Foundation improved by programmers throughout • Continued support of existing members. the world, and (c) extendibility—the business models through royalty- The Board consists of 13 seats, 6 Linux OS can be extended to niche bearing code of which are held by the Founder applications much easier than other Application Vendors Members. NTT DoCoMo serves as OS’s. The LiMo Foundation will com- • Creation of new services and busi- chair of the Board. The Executive bine these three features with the best nesses and building of a new cus- Council consists of members corre- practices of the commercial-develop- tomer base through adoption of a sponding to the Board representation ment model in the mobile industry to company’s own software and is essentially a decision-making provide participating members with a body that coordinates discussions out- globally competitive platform for 2.3 Delivered Items side the Board agenda and oversees the mobile terminals [1]. The LiMo Foundation will, in prin- work of the Architecture Council, the Operator Benefits ciple, provide members with the source Requirements Council, and the Foun- • Reduced terminal purchasing cost code of the Linux OS-based software dation Program Office. The Architec- • Shortened terminal development platform for mobile terminals on a ture Council oversees technical matters time copyright royalty-free basis. It will also and has working groups under its • Reduced support costs, greater publish the Application Program Inter- wings to perform development work compatibility, etc. for new global face (API) specifications*2 defined by on a contributory basis. The role of the services the LiMo Foundation for public use Requirements Council is to capture Mobile Terminal Manufacturer Benefits and will enable third party developers service requirements. • Reduced terminal development cost to create application products using • Formation of collaborative rela- development environments such as 2.5 Membership tionships among mobile terminal Software Development Kit (SDK)*3 There are three classes of Founda- manufacturers provided by various companies. tion membership: Founder Member, • Allows a company’s own engi- Core Member, and Associate Member. neering team to focus on product 2.4 Organization 1) Founder Member differentiation Figure 1 shows the basic organi-

Chip Vendors zation structure of the LiMo Founda- Board • Ensures a platform supporting a tion. Executive company’s own chip sets The main components of the Foun- Council • Access to mobile-terminal source dation are the Board of Directors (the Requirements Architecture Foundation code “Board”), Executive Council, Archi- Council Council Program Office Middleware Vendors tecture Council, and Requirements Working Groups • Greater opportunity for a compa- Council. It also includes the Founda- Figure 1 Basic organization structure of the ny’s own products to be adopted tion Program Office that manages the LiMo Foundation • Reduced support costs through day-to-day operations of the Founda-

*2 API specifications: Interface specifications that enable upper-level software to use OS and middleware functions. *3 SDK: A set of documents, tools, libraries, sample programs, etc. needed to create applications.

52 NTT DoCoMo Technical Journal Vol. 9 No.2 Eligible to sit on the Board for the 1) Open Source License (Common dleware functions configured as frame- first five years. Basic rights other than the Code) works and plug-ins that can be used in Board seat are the same as that of the 2) Foundation Public License (Com- common by mobile terminals. A frame- Core Member. mon Capable) work is an abstract layer that provides 2) Core Member 3) Foundation Public License (Non- functions independent of proprietary func- Basic rights include the following: eli- Common Capable) tions or proprietary hardware. Functions gible for election to the Board, eligible to 4) Proprietary License (royalty bearing) that are dependent on specific services or vote in accordance with Foundation specific hardware are implemented as Bylaws, eligible for election to all Foun- Of these, only types 1) and 2) are con- plug-ins. The LiMo Foundation platform dation Councils and to chairs of the same, sidered for inclusion as part of the Com- with a configuration consisting of frame- right to access and modify Foundation mon Code of the Foundation platform. works and plug-ins achieves a balance source code and to ship products. This is That is, products conforming to the Foun- between uniformity and flexibility. the membership class that is expected to dation platform specification must contain Figure 2 shows the configuration of be the center of Foundation activities. all Common Code. Types 3) and 4) corre- the software architecture provided by the 3) Associate Member spond to code that may not be common to LiMo Foundation [3]. The portion titled Enables participation in the Founda- all members but provides service- or geo- “Platform Scope” corresponds to the plat- tion with a low membership fee. Although graphic-market-dependent functions for form provided by the LiMo Foundation. Associate Members are not eligible for product differentiation. Common Code is The functions within Platform Scope are election to the Board, they are eligible for licensed to all members on a copyright configured as frameworks or plug-ins as election to the Requirements Council and and royalty-free basis. Non-discriminato- needed. The role of each of these func- have the right to participate in working ry royalty fees may be collected for tions is summarized below. groups. This category was established to license types 3) and 4) at the discretion of 1) Application Manager Framework/ invite participation from Independent the rights holder. Also, as a unique Application UI Framework Software Vendors (ISVs)*4. scheme of the Foundation, code con- The Application Manager Framework tributed under license types 3) and 4) may activates applications and includes a secure 2.6 IPR Policy be automatically converted to license type package installer for downloaded applica- The Intellectual Property Rights (IPR) 1) or 2) on the automatic-conversion date tions. The Application User Interface (UI) model [2] provided by the Foundation designated by the contributor at the time Framework manages user input, provides a combines open source license policy with of the contribution. This scheme aims to user interface, and includes The GNU IPR policy unique to the Foundation broaden the portion of code that can be image manipulation program ToolKit resulting in the following four types of used in common for free, thereby lower- (GTK+), a Graphical User Interface (GUI) licenses. The code listed below refers to ing the cost of Foundation products. tool kit. software code, such as source-code and 2) Registry object-code, submitted by members that is 3. Software Architecture Provides storage space for storing a component of, or is proposed to be a Overview records (system data). component of, the Foundation platform. The LiMo Foundation provides mid- 3) Conflict Management

*4 ISV: A software company not under the umbrella of certain software providers.

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Provides capture and playback ser- Applications vices for audio, images, and video and

Platform Scope manages the operational state of each Middleware of these media forms. 10) Digital Rights Management User (DRM)*6 Framework Space Provides interfaces for restricting the access and use of content such as Registry Database

DRM Framework music and video according to defined Other Frameworks Event Delivery / IPC Security Framework elephony Framework Conflict Management T Messaging Framework Multimedia Framework Networking Framework Application UI Framework

Application Manager Framework rules and decides whether data can be accessed or decoded for playback. Kernel Linux Kernel Device Drivers Modem Interface Space 11) Database

Modem Provides interfaces for performing ACID*7 (Atomic*8, Consistent*9, Isola- Figure 2 Configuration of software architecture tion*10, Durable*11) data management through data operations such as create, Resolves and manages conflicts with telephone functions. Supports net- query, update and delete. among multiple applications that are work registration, voice-call control, simultaneously requesting access to video-call control, supplementary ser- 4. Relationship between shared resources and conflicts between vices, call-charges information, and the LiMo Foundation access requests from applications and Subscriber Identity Module and User Platform and MOAP (L) system state. SIM (SIM/USIM)*5. NTT DoCoMo has been collabo- 4) Event Delivery/InterProcess 7) Networking Framework rating with NEC Corporation and Communication (IPC) A framework for controlling data Panasonic Mobile Communications Creates, filters, registers, and communications by providing inter- Co., Ltd. to develop the “MOAP (L)” issues messages for inter-process com- faces for establishing and managing software platform that can be used in munication. logical connections. common by mobile-terminal manufac- 5) Security Framework 8) Messaging Framework turers and software vendors in the Scans applications or content Manages messaging accounts and development of mobile-terminal soft- before installation and applies security profiles and provides interfaces for ware [4][5]. policy according to access rights held sending and receiving messages using The objectives of MOAP (L) and by user when attempting to access message functions such as Short Mes- the LiMo Foundation platform agree in applications or content after installa- sage Service (SMS), Multimedia Mes- terms of providing common middle- tion. saging Service (MMS), and i-mode ware functions on a platform, improv- 6) Telephony Framework mail. ing software quality, and reducing A framework concerned mostly 9) Multimedia Framework development cost.

*5 SIM/USIM: SIM is an IC card storing infor- *6 DRM: A function for protecting the copy- mation on the mobile-phone subscriber used rights of digital content by restricting redistri- mainly in the GSM system. USIM is a func- bution, preventing unauthorized copying, etc. tional extension of SIM.

54 NTT DoCoMo Technical Journal Vol. 9 No.2 Difference between these two plat- functions independent of mobile operations in conjunction with new members forms are as follows. MOAP (L) is a plat- tors. From here on, we expect to make the joining from April 2007. At NTT DoCo- form originally developed exclusively for development process even more efficient Mo, we plan to make the most of this plat- FOMA terminals and is presently not by making the common functions provid- form to reduce the development cost of being applied to any mobile terminals ed by MOAP (L) common with LiMo future mobile terminals and further other than FOMA. The LiMo Foundation Foundation. New functions needed by improve their functions. platform, on the other hand, is a platform FOMA terminals will be developed under that is greatly aware of global mobile ter- MOAP (L) to ensure innovative features. References minals adding the Vodafone Group, Furthermore, as part of our contribu- [1] LiMo Foundation, “Overview of LiMo Foun- dation,” Ver. 1.2.2, Apr. 2007. Motorola, Inc., and Samsung Electronics tions to the LiMo Foundation in the years [2] LiMo Foundation, “Foundation Intellectual Co., Ltd., as collaborating companies. to come, we aim to strike a balance Property Policy,” Annex A, Bylaws of LiMo Work is now progressing on merging between innovative features and reduction Foundation, 2 April 2007. the best functions of MOAP (L) with the of development costs through reduced [3] LiMo Foundation, “http://www.limofounda- ” best functions of other companies to con- maintenance-related cost associated with tion.org . [4] H. Tsuji et al.: ““MOAP,” Software Platform struct the LiMo Foundation platform. At troubleshooting and functional extensions, for FOMA Terminals,” NTT DoCoMo Technical NTT DoCoMo, the migration plan shown through license contibutions, etc. Journal, Vol. 7, No. 1, pp. 40–43, Jun. 2005. in Figure 3 is being studied with the aim [5] M. Yoshizawa et al.: “Expansion of “MOAP” of making the development of FOMA ter- 5. Conclusion Software Platform for Mobile Terminals,” NTT DoCoMo Technical Journal, Vol. 8, No. minals even more efficient in the future. The work of the LiMo Foundation 1, pp.15-18, Jun. 2006. The platform functions provided by will begin with the creation of a Linux- MOAP (L) are divided into unique func- based platform for mobile terminals by tions for achieving attractive FOMA func- the six Founder Members followed by the tions and common functions for achieving development of many new common func-

MOAP(L) Incorporate LiMo Migrate common functions LiMo

Unique functions MOAP (L) Common functions LiMo

LiMo Appli- Applications Applications Applications cations

LiMo LiMo LiMo MOAP (L) API MOAP (L) LiMo API MOAP (L) MOAP (L) • Incorporate LiMo • Begin adoption of • Support of LiMo compliant applications Platform configuration functions LiMo Foundation • Support of existing applications platform • Common functions: LiMo • Unique functions: MOAP (L) Figure 3 Migration from MOAP (L) to LiMo

*7 ACID: An acronym formed from the words Atom- vidual operations making up a transaction are exe- *11 Durable: Guarantees that a transaction cannot be ic (see *8), Consistent (see *9), Isolation (see cuted. cancelled once completed. *10), and Durable (see *11), the four conditions *9 Consistent: Consistency is maintained in the that must be satisfied to perform transaction pro- database at all times. cessing in a database management system. *10 Isolation: Completely separates transaction pro- *8 Atomic: Guarantees that all or none of the indi- cessing from other transactions.

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