Patent Publication Number: US-2012047223-A1

Title: Method and apparatus for distributed storage

Description:
BACKGROUND 
     Service providers and device manufacturers (e.g., wireless, cellular, etc.) are continually challenged to deliver value and convenience to consumers by, for example, providing compelling network services. Important differentiators in the industry are application and network services as well as capabilities to support and scale these services. In particular, these applications and services can include accessing and managing data utilized by one or more applications and/or services. However, supporting a larger base of users attempting to access and/or manage a growing amount of data can be technically challenging. For example, challenges can exist in determining storage locations and minimizing costs of the storage locations. Further, the increase in use of storage mechanisms for storing data increases the need for an advantageous approach to distributed data storage. 
     SOME EXAMPLE EMBODIMENTS 
     Therefore, there is a need for an approach for implementing a storage system utilizing publication and subscription interfaces. 
     According to one embodiment, a method comprises determining to publish a request for content, the request based, at least in part, on one or more criteria. The method also comprises receiving one or more responses from one or more storage blocks that have one or more subscriptions to at least one of the one or more criteria. The method further comprises determining to publish another request to transfer the content to at least one destination subscription based, at least in part, on the one or more responses. 
     According to another embodiment, an apparatus comprises at least one processor, and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause, at least in part, the apparatus to determine to publish a request for content, the request based, at least in part, on one or more criteria. The apparatus is also caused to receive one or more responses from one or more storage blocks that have one or more subscriptions to at least one of the one or more criteria. The apparatus is further caused to determine to publish another request to transfer the content to at least one destination subscription based, at least in part, on the one or more responses. 
     According to another embodiment, a computer-readable storage medium carries one or more sequences of one or more instructions which, when executed by one or more processors, cause, at least in part, an apparatus to determine to publish a request for content, the request based, at least in part, on one or more criteria. The apparatus is also caused to receive one or more responses from one or more storage blocks that have one or more subscriptions to at least one of the one or more criteria. The apparatus is further caused to determine to publish another request to transfer the content to at least one destination subscription based, at least in part, on the one or more responses. 
     According to another embodiment, an apparatus comprises means for determining to publish a request for content, the request based, at least in part, on one or more criteria. The apparatus also comprises means for receiving one or more responses from one or more storage blocks that have one or more subscriptions to at least one of the one or more criteria. The apparatus further comprises means for determining to publish another request to transfer the content to at least one destination subscription based, at least in part, on the one or more responses. 
     Still other aspects, features, and advantages of the invention are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the invention. The invention is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings: 
         FIG. 1  is a diagram of a system capable of distributed storage, according to one embodiment; 
         FIG. 2  is a diagram of the components of a server that can be utilized in implementing a service and/or storage block, according to one embodiment; 
         FIG. 3  is a flowchart of a process for retrieving content based on a publication and subscription model, according to one embodiment; 
         FIGS. 4 and 5  are flow diagram of processes for causing a storage block to publish content to a destination subscription, according to various embodiments; 
         FIG. 6  is a flow diagram of a process for replicating content using a publication and subscription model, according to one embodiment; 
         FIG. 7  is a diagram of hardware that can be used to implement an embodiment of the invention; 
         FIG. 8  is a diagram of a chip set that can be used to implement an embodiment of the invention; and 
         FIG. 9  is a diagram of a mobile terminal (e.g., handset) that can be used to implement an embodiment of the invention. 
     
    
    
     DESCRIPTION OF SOME EMBODIMENTS 
     Examples of a method, apparatus, and computer program for providing a storage system utilizing publication and subscription interfaces are disclosed. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It is apparent, however, to one skilled in the art that the embodiments of the invention may be practiced without these specific details or with an equivalent arrangement. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention. 
       FIG. 1  is a diagram of a system capable of distributed storage, according to one embodiment. Distributed storage organization allows for the storage of content at one or more locations. As such, storage can be virtualized (e.g., pertain to the abstraction of local storage from physical storage). The cost of such cloud-based storage is expected to be a portion of operating costs for internet-based services. Thus, it can be advantageous to reduce the operating costs for distributed storage systems while still maintaining a quick, efficient, and available storage system. 
     One approach to reduce the costs of a storage system is to consolidate servers and storage to reduce infrastructure investments and decrease storage and/or server management costs or centrally manage a server and storage resources to reduce administrative costs. Another approach is to reduce network congestion by removing data traffic (e.g., filtering of a network). Further, a service provider can enhance application performance and reduce backup times by offloading backup and/or other data movement from application networks. Moreover, servers and storage can be independently scaled to increase flexibility. To achieve greater availability of content, the service provider can introduce path, server, and storage failover. 
     Storage solutions can be based on one or more different types of techniques (e.g., block-based storage, distributed hash tables, linear hashing techniques, multi-tiered storage, resource pooling, etc.). In one example, in a block-based storage environment, a single block of information can be accessed using a logical unit identifier (LUN) and an offset within that LUN (e.g., a Logical Block Address (LBA)). Address mapping can be between a logical disk, e.g., a virtual disk, and a logical unit represented by one or more storage controllers. The LUN may also be a product of a virtualization in a different layer. 
     In another example, a tiered storage can store information in a database in such a way that information searched for more often is moved to a different tier, producing faster search results. When available storage capacity is pooled, system administrators no longer need to search for disks that have free space to allocate to a particular host or server. A new logical disk can be simply allocated from an available pool of resources, or an existing disk can be expanded. 
     In data-centric storage, a hash-like interface can be utilized where data (or data structures) can be stored and retrieved by an identifier (e.g., a name). This can be achieved by deterministically mapping (e.g., hashing) a data name to a geographic location within a network. Further, other storage systems, such as peer-to-peer storage systems (e.g., Cooperative File System (CFS)), linear hashing, and clustering can be utilized for data-centric storage. However, there is inadequate support for an easy and flexible data and content centric storage with fine-grained search, security, and management operation. 
     To address this problem, a system  100  of  FIG. 1  introduces the capability to provide content storage based on a publish and subscription mechanism. Such a publish and subscription mechanism can be utilized to develop an Application Programming Interface (API) to reduce the cost of storage systems. The API can abstract the internal structure and distribution of a storage solution while providing fine-grained policy and content management features. As such, storage network interfaces can be defined in terms of publish operations, subscribe operations, and actual content. This can provide a full decoupling of functions and separation of concerns. In one embodiment, only data labels or content descriptions matter in a lookup for content. Further the data labels or content descriptions can meet one or more specified non-functional requirements. 
     User equipment (UEs)  101   a - 101   n  can be utilized to access one or more services  103  (e.g., a messaging service, a social networking service, an information service, a web site, other network services, etc.) via a communication network  105   a.  In certain embodiments, the communication network  105   a  can be connected to other communication networks (e.g., communication networks  105   b - 105   n ). In other embodiments one or more of the communication networks  105  can be independent. As such, services  103  can also be connected to other services  103 , UEs  101 , storage blocks  107 , etc. via one or more communication network  105 . As used herein, the term storage block  107  refers to a device that can be utilized for storing information. Although various embodiments are described with respect to storage blocks  107  being associated with one or more servers with storage capabilities, it is contemplated that the approach described herein may be used with other devices. Further, it is noted that various embodiments are described with respect to services  103 , however it is contemplated that one or more of the functions of the service  103  can be performed by other devices or clients (e.g., UEs  101 ). Further, in certain embodiments, a communication network (e.g., communication network  105   c ) can be a high throughput network (e.g., a storage area network, a fibre channel network, a gigabit Ethernet network, etc.). In other embodiments a communication network  105  can include other communication technologies (e.g., utilization of the internet). As such, the storage blocks  107  can be located in different networks across the world. 
     In one embodiment, the UEs  101  can utilize a service  103  using an API. The service  103  can accept UE  101  requests and interface with the storage blocks  107  in a storage substrate via a publication/subscription (pub/sub) interface. In certain embodiments, the pub/sub is a messaging paradigm where publishers (senders) of messages send their messages based on one or more criteria. Published messages can be characterized into classes. These classes can be categorized without any knowledge of who the subscribers (if any) are. Subscribers express interest in one or more classes (e.g., by subscribing to the classes). As such, subscribers may only receive messages that are pertinent. Further, the subscribers may also have no knowledge of who the publishers are. As such, publishers and subscribers can be decoupled. With this approach, greater scalability can be achieved along with a more dynamic network topology. The service  103  can include a pub/sub module  109  that can utilize pub/sub primitives (e.g., simple elements associated with a pub/sub mechanism) to communicate with one or more of the storage blocks  107 . The storage blocks  107  may additionally include a pub/sub interface. Each storage block  107  can inform the services  103  (and associated control elements such as the pub/sub module  109 ) of the structure and/or availability of the storage block  107 . The pub/sub module  109  can have built-in server selection and data indexing. The index can be part of the pub/sub communications plane. 
     The storage block  107  can have a number of subblocks that each has a content descriptor (e.g., a hash or other metadata) and actual binary content associated with the descriptor. Each block or subblock may expose one or more interfaces. The blocks can include an interface for a data/content block address range that is subscribed. This allows any interested entity to publish a message that pertains to the content in the block to the block. As such, the block address range is subscribed to the data/content block address range and/or other criteria describing the content associated with the block address range. In another embodiment, the blocks include a content request type subscription that allows an entity or any entity to specifically target a content request to the storage block  107 . In certain scenarios, a Bloom filter subscription created using subblock identifiers that summarize content available on the block can be included as an interface. A Bloom filter is a space-efficient probabilistic data structure that is utilized to test whether an element is a member of a set. As such, one or more other methods of determining whether an element is a member of a set (e.g., of summarized content) is can be utilized to determine the subscription. 
     When a service  103  wishes to write to a storage block  107 , the service  103  can publish a request to write to the block (e.g., via the block address range). In certain scenarios, the publication can be for a specific address range and/or version of the content. For example, a storage block may utilize one or more versions of the content, which may be separated using a content descriptor. As such, multiple versions of the content can be implemented and stored using the system  100 . The system thus allows fine-grained access to the various versions and their replication. Thus, old versions of data or content can be moved to a permanent storage (e.g., a slow storage) if they are not accessed frequently. Version updating and replication is further detailed in  FIG. 6 . 
     When a service  103  wishes to access content from storage block  107 , the service  103  can publish a request for a certain content address on a channel. The storage blocks  107  that have a subscription to the content address will receive the request. Each storage block  107  listening can then publish a response to the request to the service  103  indicating the availability of the content. Availability can include the load of the storage block  107 , quality of service information, version information of the content, etc. In certain embodiments, the service  103  can be listening on a specified channel associated with the request, block, address, or a combination thereof. The service  103  receives the responses and formulates a content request for the actual content to the correct block (e.g., based on the response). The content request can include a subscription to publish the content to. The storage block  107  can then begin transfer of the content to the service  103  by publishing the content to the specified subscription. The service  103  and/or other services  103  or devices subscribed to the specified subscription can then receive the content. 
     In certain embodiments, a user (e.g., end-user, administrator, manager, etc.) of the UE  101  or of the service may utilize a user interface component to manage storage activities. Such a user interface can be implemented using content-based resource retrieval. For example, the user can specify content descriptors and/or meta-data, such as title names, author names, etc. rather than conventional file names. As a result, the user interface is more intuitive and can be easier to understand by enabling retrieval based on content meta-data. 
     As shown in  FIG. 1 , the system  100  comprises a user equipment (UE)  101  having connectivity to a service  103  and/or storage blocks  107  via one or more communication networks  105 . By way of example, the communication network  105  of system  100  includes one or more networks such as a data network (not shown), a wireless network (not shown), a telephony network (not shown), or any combination thereof. It is contemplated that the data network may be any local area network (LAN), metropolitan area network (MAN), wide area network (WAN), a public data network (e.g., the Internet), short range wireless network, or any other suitable packet-switched network, such as a commercially owned, proprietary packet-switched network, e.g., a proprietary cable or fiber-optic network, and the like, or any combination thereof. In addition, the wireless network may be, for example, a cellular network and may employ various technologies including enhanced data rates for global evolution (EDGE), general packet radio service (GPRS), global system for mobile communications (GSM), Internet protocol multimedia subsystem (IMS), universal mobile telecommunications system (UMTS), etc., as well as any other suitable wireless medium, e.g., worldwide interoperability for microwave access (WiMAX), Long Term Evolution (LTE) networks, code division multiple access (CDMA), wideband code division multiple access (WCDMA), wireless fidelity (WiFi), wireless LAN (WLAN), Bluetooth®, Internet Protocol (IP) data casting, satellite, mobile ad-hoc network (MANET), and the like, or any combination thereof. 
     The UE  101  is any type of mobile terminal, fixed terminal, or portable terminal including a mobile handset, station, unit, device, multimedia computer, multimedia tablet, Internet node, communicator, desktop computer, laptop computer, notebook computer, netbook computer, tablet computer, Personal Digital Assistants (PDAs), audio/video player, digital camera/camcorder, positioning device, television receiver, radio broadcast receiver, electronic book device, game device, or any combination thereof, including the accessories and peripherals of these devices, or any combination thereof. It is also contemplated that the UE  101  can support any type of interface to the user (such as “wearable” circuitry, etc.). 
     By way of example, the UE  101 , services  103 , storage blocks, etc. communicate with each other and other components of the communication networks  105  using well known, new or still developing protocols. In this context, a protocol includes a set of rules defining how the network nodes within the communication network  105  interact with each other based on information sent over the communication links. The protocols are effective at different layers of operation within each node, from generating and receiving physical signals of various types, to selecting a link for transferring those signals, to the format of information indicated by those signals, to identifying which software application executing on a computer system sends or receives the information. The conceptually different layers of protocols for exchanging information over a network are described in the Open Systems Interconnection (OSI) Reference Model. 
     Communications between the network nodes are typically effected by exchanging discrete packets of data. Each packet typically comprises (1) header information associated with a particular protocol, and (2) payload information that follows the header information and contains information that may be processed independently of that particular protocol. In some protocols, the packet includes (3) trailer information following the payload and indicating the end of the payload information. The header includes information such as the source of the packet, its destination, the length of the payload, and other properties used by the protocol. Often, the data in the payload for the particular protocol includes a header and payload for a different protocol associated with a different, higher layer of the OSI Reference Model. The header for a particular protocol typically indicates a type for the next protocol contained in its payload. The higher layer protocol is said to be encapsulated in the lower layer protocol. The headers included in a packet traversing multiple heterogeneous networks, such as the Internet, typically include a physical (layer  1 ) header, a data-link (layer  2 ) header, an internetwork (layer  3 ) header and a transport (layer  4 ) header, and various application headers (layer  5 , layer  6  and layer  7 ) as defined by the OSI Reference Model. 
     In one embodiment, service  103  may interact according to a client-server model with the UEs  101 . According to the client-server model, a client process sends a message including a request to a server process, and the server process responds by providing a service (e.g., social networking, augmented reality, messaging, etc.). The server process may also return a message with a response to the client process. Often the client process and server process execute on different computer devices, called hosts, and communicate via a network using one or more protocols for network communications. The term “server” is conventionally used to refer to the process that provides the service, or the host computer on which the process operates. Similarly, the term “client” is conventionally used to refer to the process that makes the request, or the host computer on which the process operates. As used herein, the terms “client” and “server” refer to the processes, rather than the host computers, unless otherwise clear from the context. In addition, the process performed by a server can be broken up to run as multiple processes on multiple hosts (sometimes called tiers) for reasons that include reliability, scalability, and redundancy, among others. Further, the service  103  can be considered a client of one or more storage blocks  107 . 
       FIG. 2  is a diagram of the components of a server that can be utilized in implementing a service and/or storage block, according to one embodiment, according to one embodiment. By way of example, the server  200  includes one or more components for storing and retrieving content via a pub/sub interface. It is contemplated that the functions of these components may be combined in one or more components or performed by other components of equivalent functionality. In this embodiment, the server includes control logic  201  to control processing, a pub/sub module  203  to control publication and subscription processes, a memory  205 , and a communication interface  207  to communicate with other devices. 
     Control logic  201  of the server  200  can be utilized to control one or more processes of the server  200 . The control logic  201  can further be utilized to provide a service  103  as well as provide control to utilize storage blocks  107 . For example, in a service  103 , the control logic  201  can execute code stored in memory  205  to provide the service  103 . Moreover, the control logic  201  can utilize a pub/sub module  203  to communicate via a storage substrate. The control logic  201  can be implemented on a block/disk resource level to support the content centric pub/sub storage. 
     Further, the system  100  can be implemented on different layers of a protocol stack. For example, it can be implemented as an overlay network utilizing one or more servers  200  that are Internet Protocol (IP) based. Pub/sub traffic can then be routed across the servers. The implementation can combine software and hardware features by partly replacing the internet protocol and, in place of or in addition to the internet protocol, using an Ethernet, another form of link layer addressing, etc. 
     In one embodiment, the communication interface  207  can be used to communicate via the storage substrate. Moreover, the communication interface  207  or another communication interface  207  of the server  200  can be utilized to communicate with one or more UEs  101  or other devices. Certain communications can be via methods such as an internet protocol, messaging (e.g., Short Message Service (SMS), Multimedia Messaging Service (MMS), etc.), or any other communication method (e.g., via the communication networks  105 ). 
     As noted above, the pub/sub module  203  can be utilized to send and receive messages via publications and subscriptions. The control logic  201  can subscribe the server  200  to one or more channels via the pub/sub module  203  to listen for relevant messages. Further, the control logic  201  can publish information it wishes to communicate via the pub/sub module  203  to other services  103 , storage blocks  107 , servers  200 , a combination thereof, etc. 
     In one scenario, a service  103  is implemented via a server  200 . As such, the service can execute via the control logic  201  and memory  205 . Further, the communication interface  207  can be utilized to communicate with one or more UEs  101  (e.g., via an API). When the service  103  requires information stored on one or more storage blocks  107 , the control logic  201  can utilize the pub/sub module  203  to retrieve content as further detailed in  FIGS. 3 ,  4 , and  5 . The pub/sub module  203  of the service  103  can include logic to control access and information associated with storage blocks  107 . For example, the memory  205  of can include a pub/sub routing table that provides a mapping table associated with the storage blocks  107 . 
     In another scenario, a storage block  107  can be implemented via a server  200 . A memory  205  of the storage block  107  can store content that can be retrieved by one or more services  103 , clients, etc. The content can be stored in a volatile memory and/or a non-volatile memory. Further, the content may be stored in a database separate from a server  200  associated with the storage block  107 . 
     As previously noted, the storage block  107  can provide an interface for accessing content via a block address range subscription, a content request type subscription, a Bloom filter subscription, or a combination thereof. In certain scenarios, the block address range subscription can refer to one or more address ranges for content for which the storage block  107  is subscribed. Further, the content request type subscription can include a content descriptor associated with the content (e.g., in metadata associated with the content). For example, a piece of content associated with a particular person in a social networking environment can include metadata specifying the person (e.g., a name of the person, a unique identifier to the person such as an e-mail account, etc.). In another example, a piece of content associated with an encyclopedia can be organized via one or more categories of content types (e.g., a historical time period, a name, a genus, a species, etc.). The Bloom filter subscription can be utilized to determine whether a content type stored in a storage block  107  is part of a content type that a service  103  is looking for. In certain embodiments, a hash or other lookup method can be utilized to perform the determination. Content metadata can be implemented via one or more different technologies, such as extensible markup language (XML), Resource Description Framework (RDF) graphs, etc. The storage block  107  can announce its availability by publishing its status via a control channel, which can be monitored by services  103 . 
       FIG. 3  is a flowchart of a process for retrieving content based on a publication and subscription model, according to one embodiment. In one embodiment, the control logic  201  of a service  103  performs the process  300  and is implemented in, for instance, a chip set including a processor and a memory as shown in  FIG. 8 . As such, the control logic  201  can provide means for accomplishing various parts of the process  300  as well as means for accomplishing other processes in conjunction with other components of a server  200  or other device. 
     A service  103  can receive a request for services from a UE  101 . The service  103  may determine that the service  103  requires information from a storage block  107  to provide the service  103 . As such, the control logic  201  can determine to publish a request for the content, the request based, at least in part, on one or more criteria (step  301 ). The criteria can be based, at least in part, on an address range associated with the content, a content request type (e.g., metadata), a probabilistic analysis, a combination thereof, etc. Moreover, the request can be based on a routing table stored in a memory  205  associated with the service  103 . For example, the service  103  can narrow down which channels to publish the request to based on the routing table. 
     The control logic  201  can then receive one or more responses from one or more storage blocks that have one or more subscriptions to the channels the request was published on based on the one or more criteria (step  303 ). The one or more responses can include information regarding structure, availability, a combination thereof, etc. of the storage block. Availability can include a determination of whether the service  103 , UE  101 , or a particular user of the service  103  has access to the content, an availability of resources based on storage block load, a determination of whether the storage block  107  has access to the content, or a combination thereof. Further, the responses can include one or more quality of service parameters. Moreover, one or more quality of service parameters can be sent via the request, wherein the availability is based on whether the storage block meets the quality of service parameters. Example quality of service parameters include bandwidth available, local lookup time, storage block load, etc. 
     Then, at step  305 , the control logic  201  can determine that the content is available from one of the storage blocks  107 . This can be based on the response received from the one or more storage blocks  107 . The received response can additionally include Meta-data that can be utilized to determine that the content is available. The control logic  201  can then be utilized to generate a request for a content transfer for the content from a particular storage block or a set of storage blocks that include the content. Then, the control logic  201  can cause publication of another request to transfer the content to at least one destination subscription (e.g., a subscription that the service  103  monitors) based, at least in part, on the one or more responses (step  307 ). As noted above, the other request can be based on the availability information associated with the storage blocks. 
     At step  309 , the control logic  201  receives the content at the destination subscription(s). In certain embodiments, the control logic  201  may not monitor the subscription and another service  103  and/or UE  101  monitors the destination subscription for the information. Further, the content can be unicast on a channel or multicast on one or more channels from at least one of the storage blocks  107  that responded. In other embodiments, the content can be transferred using another protocol. 
     The service  103  may additionally modify the content and/or add additional content (e.g., by updating a document associated with the content). As such, the control logic  201  can determine a version associated with the content (step  311 ). Further, when publishing a request for content, a version of the content can be utilized in retrieving desired content. The version can be incremented when modified content is stored in the storage blocks  107  as further described in  FIG. 6 . Moreover, storage based on versions can be directed by the control logic  201  (step  313 ). For example, a frequency of access to the versions of the content can be determined. Based on the frequency or other criteria, the control logic  201  can determine to archive one or more of the versions. In one example, old or less utilized versions can be stored on a slower or more permanent (e.g., less volatile) storage block  107  while newer or more frequently used versions are stored on faster storage blocks  107  and/or caches. 
     In certain embodiments, the service can receive the content from caches as well as the storage blocks  107 . Cache can be discovered by publishing a message using metadata that is subscribed to by the cache. The cache can respond in the in the same way as the storage blocks  107 . As such, in certain embodiments, the cache can be considered a storage block  107 . In certain scenarios, the cache can be local to hardware associated with the service  103 , execute faster (e.g., in volatile memory), have greater bandwidth (e.g., based on a network type), etc. The cache can be populated as one or more services  103  retrieve content. 
     Moreover, in certain embodiments, the content from one storage block  107  can be split to another storage block  107  to balance utilization. This can allow part of an overloaded storage block  107  to be moved to a new storage block  107 . When an overload or potential overload (e.g., based on a predetermined load threshold) is determined, the overloaded and new storage block can reallocate the address spaces covered by each respective storage block. The old and new storage blocks can then announce their respective address spaces via one or more control channels to services  103  and/or other pub/sub controllers. The announcement may additionally include publication of their status, control channels to which they subscribe, etc. In certain examples, the split can be based on reasons other than overload (e.g., rebalancing based on the introduction of one or more new storage blocks  107 ). 
       FIG. 4  is a flow diagram of a process for causing a storage block to publish content to a destination subscription, according to one embodiment. In one embodiment, the control logic  201  of a client  401  and/or storage block  107  performs the process  400  and is implemented in, for instance, a chip set including a processor and a memory as shown in  FIG. 8 . As such, the control logic  201  can provide means for accomplishing various parts of the process  400  as well as means for accomplishing other processes in conjunction with other components of a server  200  or other device. 
     The client  401  can be any device that utilizes a storage system including one or more storage blocks  107 . For example, the client  401  can be a service  103 , a UE  101 , other computing devices, etc. Both the client  401  and storage block  107  may be implemented, at least in part, on a device such as a server  200 . 
     At steps  403  and  405 , the client  401  can publish a request for a block. The request can include a block address or a range of block addresses (e.g., as in step  403 ) or a request based on a subblock identifier associated with a filter (e.g., a Bloom filter). By way of example, content centric block addresses can be associated with or represented by names, flat labels (e.g., hashes), probabilistic set representations (e.g., Bloom filters), etc. A storage block  107  subscribed to the control channels associated with the publication can receive the request. 
     The storage block  107  then determines what content associated with the request is available on the storage block  107 . The storage block  107  formulates a request response message indicating availability of the content and publishes the request response message (step  407 ). The response request can include Meta-data that includes one or more content types associated with the address range that the storage block  107  includes. 
     The client  401  receives the block request response and determines a specific content request based on one or more content request types provided in the request response. Then, the client  401  can choose the proper block based on the content type descriptor to request. A request for content transfer based on the content type descriptor is then published (step  409 ). The request can include a destination subscription to publish the content to. In response to the request, the storage block  107  can determine which content is associated with the content type request and publish the content to the destination subscription. The destination subscription may be multicast to more than one locations (e.g., to the client  401 , more than one client, etc.). Multicasting can be via a single data channel subscribed to by multiple clients  401 , multiple data channels, or combinations thereof. 
       FIG. 5  is a flow diagram of a process for causing a storage block to publish content to a destination subscription, according to one embodiment. In one embodiment, the control logic  201  of a client  501  and/or storage block  107  performs the process  500  and is implemented in, for instance, a chip set including a processor and a memory as shown in  FIG. 8 . As such, the control logic  201  can provide means for accomplishing various parts of the process  500  as well as means for accomplishing other processes in conjunction with other components of a server  200  or other device. As noted previously, client  401  can be any device that utilizes a storage system including one or more storage blocks  107 . 
     At step  503 , the client  501  can publish a request for a block via a block address. The request can include a block address or a range of block addresses. Storage blocks  107   a,    107   b  subscribed to the control channels associated with the publication can receive the request. As such, the storage blocks  107   a,    107   b  may have overlapping address ranges to which they subscribe and/or store content for. 
     The storage blocks  107   a,    107   b  then determine what content associated with the request is available on the respective storage blocks  107   a,    107   b.  The storage blocks  107   a,    107   b  formulate a request response message indicating availability of the content and publish the request response message (step  505 ). The response request can include Meta-data that includes one or more content types associated with the address range that the respective storage blocks  107   a,    107   b  include. In certain embodiments, more than one of the storage blocks  107  respond, in other scenarios zero or one storage blocks respond (e.g., because the requested content is not included in the storage block  107 ). 
     The client  501  receives the block request response(s) and determines a specific content request based on one or more content request types provided in the request response. Both responses may be published on the same channel that the client  501  subscribes to. Then, the client  501  can choose the proper block based on the content type descriptor to request. In this scenario, the client  501  chooses storage block  107   a.  A request for content transfer based on the content type descriptor is then published (step  507 ) to the storage block  107   a.    
     As noted previously, the request can include a destination subscription to publish the content to. In response to the request, the storage block  107   a  can determine which content is associated with the content type request and publish the content to the destination subscription. This embodiment shows one example of how two storage blocks  107  with a subscription to the same block address range can be utilized in harmony. More than two storage blocks  107  can be utilized in this manner. 
       FIG. 6  is a flow diagram of a process for replicating content using a publication and subscription model, according to one embodiment. In this embodiment, the client  601  can be utilized to update content at one or more storage blocks  107   a,    107   b.  The client  601  can determine to store a piece of content. The content can be an updated version of a piece of content stored on a storage block  107  or the content can be new content. The client  601  can determine a subscription block address range associated with the content based on one or more descriptors associated with the content. The client  601  then publishes a notification of an update for the block address or block address range on a control channel associated with the address range (step  603 ). Storage blocks  107  that subscribe to the address range receive the notification. The storage blocks  107  can then determine to request a content transfer for the update. At step  605 , the respective storage blocks  107   a,    107   b  can publish a request for content transfer to a channel associated with the client  601 . In certain embodiments, the associated channel is a parameter passed in the update notification. Further, the request for content transfer may additionally include a destination subscription for the client  601  to transfer the update data. The client  601  executes the request by publishing the update content with the specified address or address range specified (step  607 ). The specified content can be published to a single channel for all storage blocks  107  or separate data channels for each requested update. 
     With the above approaches, storage can efficiently be data and content centric. As such, indexing can be implicit based on the manner that content is stored and discovered (e.g., by finding a specific subblock to transfer content separately from transferring the content). Moreover, because of the content centric nature of the system, fine-grained content-aware management operations can be implemented. Further, because the content descriptor is decoupled from the actual content, the system is more apt to dynamic configurations. 
     The processes described herein for providing a storage system utilizing publication and subscription interfaces may be advantageously implemented via software, hardware, firmware or a combination of software and/or firmware and/or hardware. For example, the processes described herein, may be advantageously implemented via processor(s), Digital Signal Processing (DSP) chip, an Application Specific Integrated Circuit (ASIC), Field Programmable Gate Arrays (FPGAs), etc. Such exemplary hardware for performing the described functions is detailed below. 
       FIG. 7  illustrates a computer system  700  upon which an embodiment of the invention may be implemented. Although computer system  700  is depicted with respect to a particular device or equipment, it is contemplated that other devices or equipment (e.g., network elements, servers, etc.) within  FIG. 7  can deploy the illustrated hardware and components of system  700 . Computer system  700  is programmed (e.g., via computer program code or instructions) to provide a storage system utilizing publication and subscription interfaces as described herein and includes a communication mechanism such as a bus  710  for passing information between other internal and external components of the computer system  700 . Information (also called data) is represented as a physical expression of a measurable phenomenon, typically electric voltages, but including, in other embodiments, such phenomena as magnetic, electromagnetic, pressure, chemical, biological, molecular, atomic, sub-atomic and quantum interactions. For example, north and south magnetic fields, or a zero and non-zero electric voltage, represent two states (0, 1) of a binary digit (bit). Other phenomena can represent digits of a higher base. A superposition of multiple simultaneous quantum states before measurement represents a quantum bit (qubit). A sequence of one or more digits constitutes digital data that is used to represent a number or code for a character. In some embodiments, information called analog data is represented by a near continuum of measurable values within a particular range. Computer system  700 , or a portion thereof, constitutes a means for performing one or more steps of providing a storage system utilizing publication and subscription interfaces. 
     A bus  710  includes one or more parallel conductors of information so that information is transferred quickly among devices coupled to the bus  710 . One or more processors  702  for processing information are coupled with the bus  710 . 
     A processor (or multiple processors)  702  performs a set of operations on information as specified by computer program code related to providing a storage system utilizing publication and subscription interfaces. The computer program code is a set of instructions or statements providing instructions for the operation of the processor and/or the computer system to perform specified functions. The code, for example, may be written in a computer programming language that is compiled into a native instruction set of the processor. The code may also be written directly using the native instruction set (e.g., machine language). The set of operations include bringing information in from the bus  710  and placing information on the bus  710 . The set of operations also typically include comparing two or more units of information, shifting positions of units of information, and combining two or more units of information, such as by addition or multiplication or logical operations like OR, exclusive OR (XOR), and AND. Each operation of the set of operations that can be performed by the processor is represented to the processor by information called instructions, such as an operation code of one or more digits. A sequence of operations to be executed by the processor  702 , such as a sequence of operation codes, constitute processor instructions, also called computer system instructions or, simply, computer instructions. Processors may be implemented as mechanical, electrical, magnetic, optical, chemical or quantum components, among others, alone or in combination. 
     Computer system  700  also includes a memory  704  coupled to bus  710 . The memory  704 , such as a random access memory (RAM) or other dynamic storage device, stores information including processor instructions for providing a storage system utilizing publication and subscription interfaces. Dynamic memory allows information stored therein to be changed by the computer system  700 . RAM allows a unit of information stored at a location called a memory address to be stored and retrieved independently of information at neighboring addresses. The memory  704  is also used by the processor  702  to store temporary values during execution of processor instructions. The computer system  700  also includes a read only memory (ROM)  706  or other static storage device coupled to the bus  710  for storing static information, including instructions, that is not changed by the computer system  700 . Some memory is composed of volatile storage that loses the information stored thereon when power is lost. Also coupled to bus  710  is a non-volatile (persistent) storage device  708 , such as a magnetic disk, optical disk or flash card, for storing information, including instructions, that persists even when the computer system  700  is turned off or otherwise loses power. 
     Information, including instructions for providing a storage system utilizing publication and subscription interfaces, is provided to the bus  710  for use by the processor from an external input device  712 , such as a keyboard containing alphanumeric keys operated by a human user, or a sensor. A sensor detects conditions in its vicinity and transforms those detections into physical expression compatible with the measurable phenomenon used to represent information in computer system  700 . Other external devices coupled to bus  710 , used primarily for interacting with humans, include a display device  714 , such as a cathode ray tube (CRT) or a liquid crystal display (LCD), or plasma screen or printer for presenting text or images, and a pointing device  716 , such as a mouse or a trackball or cursor direction keys, or motion sensor, for controlling a position of a small cursor image presented on the display  714  and issuing commands associated with graphical elements presented on the display  714 . In some embodiments, for example, in embodiments in which the computer system  700  performs all functions automatically without human input, one or more of external input device  712 , display device  714  and pointing device  716  is omitted. 
     In the illustrated embodiment, special purpose hardware, such as an application specific integrated circuit (ASIC)  720 , is coupled to bus  710 . The special purpose hardware is configured to perform operations not performed by processor  702  quickly enough for special purposes. Examples of application specific ICs include graphics accelerator cards for generating images for display  714 , cryptographic boards for encrypting and decrypting messages sent over a network, speech recognition, and interfaces to special external devices, such as robotic arms and medical scanning equipment that repeatedly perform some complex sequence of operations that are more efficiently implemented in hardware. 
     Computer system  700  also includes one or more instances of a communications interface  770  coupled to bus  710 . Communication interface  770  provides a one-way or two-way communication coupling to a variety of external devices that operate with their own processors, such as printers, scanners and external disks. In general the coupling is with a network link  778  that is connected to a local network  780  to which a variety of external devices with their own processors are connected. For example, communication interface  770  may be a parallel port or a serial port or a universal serial bus (USB) port on a personal computer. In some embodiments, communications interface  770  is an integrated services digital network (ISDN) card or a digital subscriber line (DSL) card or a telephone modem that provides an information communication connection to a corresponding type of telephone line. In some embodiments, a communication interface  770  is a cable modem that converts signals on bus  710  into signals for a communication connection over a coaxial cable or into optical signals for a communication connection over a fiber optic cable. As another example, communications interface  770  may be a local area network (LAN) card to provide a data communication connection to a compatible LAN, such as Ethernet. Wireless links may also be implemented. For wireless links, the communications interface  770  sends or receives or both sends and receives electrical, acoustic or electromagnetic signals, including infrared and optical signals, that carry information streams, such as digital data. For example, in wireless handheld devices, such as mobile telephones like cell phones, the communications interface  770  includes a radio band electromagnetic transmitter and receiver called a radio transceiver. In certain embodiments, the communications interface  770  enables connection to the communication network  105  for UE  101 , server  200 , service  103 , storage block  107 , or a combination thereof. 
     The term “computer-readable medium” as used herein refers to any medium that participates in providing information to processor  702 , including instructions for execution. Such a medium may take many forms, including, but not limited to computer-readable storage medium (e.g., non-volatile media, volatile media), and transmission media. Non-transitory media, such as non-volatile media, include, for example, optical or magnetic disks, such as storage device  708 . Volatile media include, for example, dynamic memory  704 . Transmission media include, for example, coaxial cables, copper wire, fiber optic cables, and carrier waves that travel through space without wires or cables, such as acoustic waves and electromagnetic waves, including radio, optical and infrared waves. Signals include man-made transient variations in amplitude, frequency, phase, polarization or other physical properties transmitted through the transmission media. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, CDRW, DVD, any other optical medium, punch cards, paper tape, optical mark sheets, any other physical medium with patterns of holes or other optically recognizable indicia, a RAM, a PROM, an EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave, or any other medium from which a computer can read. The term computer-readable storage medium is used herein to refer to any computer-readable medium except transmission media. 
     Logic encoded in one or more tangible media includes one or both of processor instructions on a computer-readable storage media and special purpose hardware, such as ASIC  720 . 
     Network link  778  typically provides information communication using transmission media through one or more networks to other devices that use or process the information. For example, network link  778  may provide a connection through local network  780  to a host computer  782  or to equipment  784  operated by an Internet Service Provider (ISP). ISP equipment  784  in turn provides data communication services through the public, world-wide packet-switching communication network of networks now commonly referred to as the Internet  790 . 
     A computer called a server host  792  connected to the Internet hosts a process that provides a service in response to information received over the Internet. For example, server host  792  hosts a process that provides information representing video data for presentation at display  714 . It is contemplated that the components of system  700  can be deployed in various configurations within other computer systems, e.g., host  782  and server  792 . 
     At least some embodiments of the invention are related to the use of computer system  700  for implementing some or all of the techniques described herein. According to one embodiment of the invention, those techniques are performed by computer system  700  in response to processor  702  executing one or more sequences of one or more processor instructions contained in memory  704 . Such instructions, also called computer instructions, software and program code, may be read into memory  704  from another computer-readable medium such as storage device  708  or network link  778 . Execution of the sequences of instructions contained in memory  704  causes processor  702  to perform one or more of the method steps described herein. In alternative embodiments, hardware, such as ASIC  720 , may be used in place of or in combination with software to implement the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware and software, unless otherwise explicitly stated herein. 
     The signals transmitted over network link  778  and other networks through communications interface  770 , carry information to and from computer system  700 . Computer system  700  can send and receive information, including program code, through the networks  780 ,  790  among others, through network link  778  and communications interface  770 . In an example using the Internet  790 , a server host  792  transmits program code for a particular application, requested by a message sent from computer  700 , through Internet  790 , ISP equipment  784 , local network  780  and communications interface  770 . The received code may be executed by processor  702  as it is received, or may be stored in memory  704  or in storage device  708  or other non-volatile storage for later execution, or both. In this manner, computer system  700  may obtain application program code in the form of signals on a carrier wave. 
     Various forms of computer readable media may be involved in carrying one or more sequence of instructions or data or both to processor  702  for execution. For example, instructions and data may initially be carried on a magnetic disk of a remote computer such as host  782 . The remote computer loads the instructions and data into its dynamic memory and sends the instructions and data over a telephone line using a modem. A modem local to the computer system  700  receives the instructions and data on a telephone line and uses an infra-red transmitter to convert the instructions and data to a signal on an infra-red carrier wave serving as the network link  778 . An infrared detector serving as communications interface  770  receives the instructions and data carried in the infrared signal and places information representing the instructions and data onto bus  710 . Bus  710  carries the information to memory  704  from which processor  702  retrieves and executes the instructions using some of the data sent with the instructions. The instructions and data received in memory  704  may optionally be stored on storage device  708 , either before or after execution by the processor  702 . 
       FIG. 8  illustrates a chip set or chip  800  upon which an embodiment of the invention may be implemented. Chip set  800  is programmed to provide a storage system utilizing publication and subscription interfaces as described herein and includes, for instance, the processor and memory components described with respect to  FIG. 7  incorporated in one or more physical packages (e.g., chips). By way of example, a physical package includes an arrangement of one or more materials, components, and/or wires on a structural assembly (e.g., a baseboard) to provide one or more characteristics such as physical strength, conservation of size, and/or limitation of electrical interaction. It is contemplated that in certain embodiments the chip set  800  can be implemented in a single chip. It is further contemplated that in certain embodiments the chip set or chip  800  can be implemented as a single “system on a chip.” It is further contemplated that in certain embodiments a separate ASIC would not be used, for example, and that all relevant functions as disclosed herein would be performed by a processor or processors. Chip set or chip  800 , or a portion thereof, constitutes a means for performing one or more steps of providing user interface navigation information associated with the availability of functions. Chip set or chip  800 , or a portion thereof, constitutes a means for performing one or more steps of providing a storage system utilizing publication and subscription interfaces. 
     In one embodiment, the chip set or chip  800  includes a communication mechanism such as a bus  801  for passing information among the components of the chip set  800 . A processor  803  has connectivity to the bus  801  to execute instructions and process information stored in, for example, a memory  805 . The processor  803  may include one or more processing cores with each core configured to perform independently. A multi-core processor enables multiprocessing within a single physical package. Examples of a multi-core processor include two, four, eight, or greater numbers of processing cores. Alternatively or in addition, the processor  803  may include one or more microprocessors configured in tandem via the bus  801  to enable independent execution of instructions, pipelining, and multithreading. The processor  803  may also be accompanied with one or more specialized components to perform certain processing functions and tasks such as one or more digital signal processors (DSP)  807 , or one or more application-specific integrated circuits (ASIC)  809 . A DSP  807  typically is configured to process real-world signals (e.g., sound) in real time independently of the processor  803 . Similarly, an ASIC  809  can be configured to performed specialized functions not easily performed by a more general purpose processor. Other specialized components to aid in performing the inventive functions described herein may include one or more field programmable gate arrays (FPGA) (not shown), one or more controllers (not shown), or one or more other special-purpose computer chips. 
     In one embodiment, the chip set or chip  800  includes merely one or more processors and some software and/or firmware supporting and/or relating to and/or for the one or more processors. 
     The processor  803  and accompanying components have connectivity to the memory  805  via the bus  801 . The memory  805  includes both dynamic memory (e.g., RAM, magnetic disk, writable optical disk, etc.) and static memory (e.g., ROM, CD-ROM, etc.) for storing executable instructions that when executed perform the inventive steps described herein to provide a storage system utilizing publication and subscription interfaces. The memory  805  also stores the data associated with or generated by the execution of the inventive steps. 
       FIG. 9  is a diagram of exemplary components of a mobile terminal (e.g., handset) for communications, which is capable of operating in the system of  FIG. 1 , according to one embodiment. In some embodiments, mobile terminal  901 , or a portion thereof, constitutes a means for performing one or more steps of receiving content based on a pub/sub storage system. Generally, a radio receiver is often defined in terms of front-end and back-end characteristics. The front-end of the receiver encompasses all of the Radio Frequency (RF) circuitry whereas the back-end encompasses all of the base-band processing circuitry. As used in this application, the term “circuitry” refers to both: (1) hardware-only implementations (such as implementations in only analog and/or digital circuitry), and (2) to combinations of circuitry and software (and/or firmware) (such as, if applicable to the particular context, to a combination of processor(s), including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions). This definition of “circuitry” applies to all uses of this term in this application, including in any claims. As a further example, as used in this application and if applicable to the particular context, the term “circuitry” would also cover an implementation of merely a processor (or multiple processors) and its (or their) accompanying software/or firmware. The term “circuitry” would also cover if applicable to the particular context, for example, a baseband integrated circuit or applications processor integrated circuit in a mobile phone or a similar integrated circuit in a cellular network device or other network devices. 
     Pertinent internal components of the telephone include a Main Control Unit (MCU)  903 , a Digital Signal Processor (DSP)  905 , and a receiver/transmitter unit including a microphone gain control unit and a speaker gain control unit. A main display unit  907  provides a display to the user in support of various applications and mobile terminal functions that perform or support the steps of receiving content based on a pub/sub storage system. The display  907  includes display circuitry configured to display at least a portion of a user interface of the mobile terminal (e.g., mobile telephone). Additionally, the display  907  and display circuitry are configured to facilitate user control of at least some functions of the mobile terminal. An audio function circuitry  909  includes a microphone  911  and microphone amplifier that amplifies the speech signal output from the microphone  911 . The amplified speech signal output from the microphone  911  is fed to a coder/decoder (CODEC)  913 . 
     A radio section  915  amplifies power and converts frequency in order to communicate with a base station, which is included in a mobile communication system, via antenna  917 . The power amplifier (PA)  919  and the transmitter/modulation circuitry are operationally responsive to the MCU  903 , with an output from the PA  919  coupled to the duplexer  921  or circulator or antenna switch, as known in the art. The PA  919  also couples to a battery interface and power control unit  920 . 
     In use, a user of mobile terminal  901  speaks into the microphone  911  and his or her voice along with any detected background noise is converted into an analog voltage. The analog voltage is then converted into a digital signal through the Analog to Digital Converter (ADC)  923 . The control unit  903  routes the digital signal into the DSP  905  for processing therein, such as speech encoding, channel encoding, encrypting, and interleaving. In one embodiment, the processed voice signals are encoded, by units not separately shown, using a cellular transmission protocol such as global evolution (EDGE), general packet radio service (GPRS), global system for mobile communications (GSM), Internet protocol multimedia subsystem (IMS), universal mobile telecommunications system (UMTS), etc., as well as any other suitable wireless medium, e.g., microwave access (WiMAX), Long Term Evolution (LTE) networks, code division multiple access (CDMA), wideband code division multiple access (WCDMA), wireless fidelity (WiFi), satellite, and the like. 
     The encoded signals are then routed to an equalizer  925  for compensation of any frequency-dependent impairments that occur during transmission though the air such as phase and amplitude distortion. After equalizing the bit stream, the modulator  927  combines the signal with a RF signal generated in the RF interface  929 . The modulator  927  generates a sine wave by way of frequency or phase modulation. In order to prepare the signal for transmission, an up-converter  931  combines the sine wave output from the modulator  927  with another sine wave generated by a synthesizer  933  to achieve the desired frequency of transmission. The signal is then sent through a PA  919  to increase the signal to an appropriate power level. In practical systems, the PA  919  acts as a variable gain amplifier whose gain is controlled by the DSP  905  from information received from a network base station. The signal is then filtered within the duplexer  921  and optionally sent to an antenna coupler  935  to match impedances to provide maximum power transfer. Finally, the signal is transmitted via antenna  917  to a local base station. An automatic gain control (AGC) can be supplied to control the gain of the final stages of the receiver. The signals may be forwarded from there to a remote telephone which may be another cellular telephone, other mobile phone or a land-line connected to a Public Switched Telephone Network (PSTN), or other telephony networks. 
     Voice signals transmitted to the mobile terminal  901  are received via antenna  917  and immediately amplified by a low noise amplifier (LNA)  937 . A down-converter  939  lowers the carrier frequency while the demodulator  941  strips away the RF leaving only a digital bit stream. The signal then goes through the equalizer  925  and is processed by the DSP  905 . A Digital to Analog Converter (DAC)  943  converts the signal and the resulting output is transmitted to the user through the speaker  945 , all under control of a Main Control Unit (MCU)  903 —which can be implemented as a Central Processing Unit (CPU) (not shown). 
     The MCU  903  receives various signals including input signals from the keyboard  947 . The keyboard  947  and/or the MCU  903  in combination with other user input components (e.g., the microphone  911 ) comprise a user interface circuitry for managing user input. The MCU  903  runs a user interface software to facilitate user control of at least some functions of the mobile terminal  901  to receive content based on a pub/sub storage system. The MCU  903  also delivers a display command and a switch command to the display  907  and to the speech output switching controller, respectively. Further, the MCU  903  exchanges information with the DSP  905  and can access an optionally incorporated SIM card  949  and a memory  951 . In addition, the MCU  903  executes various control functions required of the terminal. The DSP  905  may, depending upon the implementation, perform any of a variety of conventional digital processing functions on the voice signals. Additionally, DSP  905  determines the background noise level of the local environment from the signals detected by microphone  911  and sets the gain of microphone  911  to a level selected to compensate for the natural tendency of the user of the mobile terminal  901 . 
     The CODEC  913  includes the ADC  923  and DAC  943 . The memory  951  stores various data including call incoming tone data and is capable of storing other data including music data received via, e.g., the global Internet. The software module could reside in RAM memory, flash memory, registers, or any other form of writable storage medium known in the art. The memory device  951  may be, but not limited to, a single memory, CD, DVD, ROM, RAM, EEPROM, optical storage, or any other non-volatile storage medium capable of storing digital data. 
     An optionally incorporated SIM card  949  carries, for instance, important information, such as the cellular phone number, the carrier supplying service, subscription details, and security information. The SIM card  949  serves primarily to identify the mobile terminal  901  on a radio network. The card  949  also contains a memory for storing a personal telephone number registry, text messages, and user specific mobile terminal settings. 
     While the invention has been described in connection with a number of embodiments and implementations, the invention is not so limited but covers various obvious modifications and equivalent arrangements, which fall within the purview of the appended claims. Although features of the invention are expressed in certain combinations among the claims, it is contemplated that these features can be arranged in any combination and order.