Methods & arrangements for providing efficient information transfer over a limited-speed communications link

• US 20020138565A1
• Filed: 03/14/2002
• Published: 09/26/2002
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: Mavenir Systems Incorporated (Mavenir Group Holdings Ltd.)
• Original Assignee: First Hop Oy (Mavenir Group Holdings Ltd.)
• Inventors: Koponen, Juha, Kari, Hannu, Khachtchanski, Victor, Mallat, Hannu, Auvinen, Olli, Rasanen, Juhana, Hamalainen, Mikko, Kustov, Andrei
• Granted Patent: US 7,162,535 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/289 Intermediate processing functionally located close to the data consumer application, e.g. in same machine, in same home or in same sub-network
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/567 Integrating service provisioning from a plurality of service providers
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Methods and arrangements are disclosed for transferring digital data over a limited speed communications link between a client side subarrangement (401) and a server side subarrangement (402). Within the client side subarrangement (401) a client application (411, 502) receives and transmits digital data using a first communications protocol stack (412, 503, 504, 505) and within the server side subarrangement (402) a server application (426, 572) receives and transmits digital data using the first communications protocol stack (425, 573, 574, 575). Digital data is transferred between the client application (411, 502) and the server application (426, 572) through a client proxy (511) within the client side subarrangement (401) and an access gateway (551) within the server side subarrangement (402). Said client proxy (511) performs protocol conversions between the first communications protocol stack (412, 503, 504, 505) and a second communications protocol stack (415, 521, 522, 523, 524, 525, 526) that corresponds to a bandwidth efficiency that is better than a bandwidth efficiency to which the first communications protocol corresponds. Said access gateway (551) performs protocol conversions between the first (425, 573, 574, 575) and second communications protocol stacks (422, 553, 554, 555, 556, 557, 558) so that between said client proxy (511) and said access gateway (551) digital data are transferred according to the second communications protocol stack.

Claims

1. An arrangement for transferring digital data over a limited speed communications link, comprising:

a client side subarrangement,

a server side subarrangement located at a different side of the limited speed communications link than the client side subarrangement,

within the client side subarrangement a client application arranged to receive and transmit digital data using a first communications protocol stack, and

within the server side subarrangement a server application arranged to receive and transmit digital data using the first communications protocol stack;

within the client side subarrangement a client proxy arranged to perform protocol conversions between the first communications protocol stack and a second communications protocol stack, and

within the server side subarrangement an access gateway arranged to perform protocol conversions between the first communications protocol stack and the second communications protocol stack;

wherein;

said client proxy and said access gateway are arranged to convey transferred digital data between the client application and the server application so that between said client proxy and said access gateway digital data are transferred according to the second communications protocol stack, and

said second communications protocol stack corresponds to a bandwidth efficiency that is better than a bandwidth efficiency to which the first communications protocol stack corresponds.

2. An arrangement according to claim 1, wherein:

said client proxy comprises a first protocol stack arranged to correspond to the client application in its use of the first communications protocol stack,

said client proxy comprises a second protocol stack arranged to correspond to said access gateway in its use of the second communications protocol stack,

said client proxy comprises an application layer entity located on top of said first and second protocol stacks and arranged to process digital data during protocol conversions,

said access gateway comprises a first protocol stack arranged to correspond to the server application in its use of the first communications protocol stack,

said access gateway comprises a second protocol stack arranged to correspond to said client proxy in its use of the second communications protocol stack, and

said access gateway comprises an application layer entity located on top of said first and second protocol stacks and arranged to process digital data during protocol conversions.

3. An arrangement according to claim 2, wherein:

the application layer entity of the client proxy comprises;

a connection handler arranged to handle the processing of requests and responses conveyed through the client proxy,

coupled to said connection handler a cache memory arranged to store previously handled digital data, and

coupled to said connection handler at least one protocol handler arranged to perform conversions between the first and second communications protocol stacks; and

the application layer entity of the access gateway comprises;

a connection handler arranged to handle the processing of requests and responses conveyed through the access gateway,

coupled to said connection handler at least one cache memory arranged to store previously handled digital data, and

coupled to said connection handler at least one protocol handler arranged to perform conversions between the first and second communications protocol stacks.

4. An arrangement according to claim 3, wherein:

the application layer entity of the client proxy comprises, coupled to said connection handler, a number of protocol handlers each of which is arranged to perform conversions between a different first communications protocol and the second communications protocol stack, and

the application layer entity of the access gateway comprises, coupled to said connection handler, a number of protocol handlers each of which is arranged to perform conversions between a different first communications protocol and the second communications protocol stack.

5. An arrangement according to claim 3, comprising multiplexing means at both the application layer entity of the client proxy and the application layer entity of the access gateway, said multiplexing means being arranged to multiplex several logically separate connections between the client proxy and the access gateway into a single connection therebetween.

6. An arrangement according to claim 1, wherein the first communications protocol stack is a combination of HTTP over TCP/IP and the second communications protocol stack is WAP.

7. A client side arrangement for transferring digital data over a limited speed communications link in communication with a server side arrangement located at a different side of the limited speed communications link than the client side arrangement, the client side arrangement comprising:

a client application arranged to receive and transmit digital data using a first communications protocol stack, and

a client proxy arranged to perform protocol conversions between the first communications protocol stack and a second communications protocol stack;

wherein;

said client proxy is arranged to convey transferred digital data between the client application and the server side arrangement so that between said client proxy and said server side arrangement digital data are transferred according to the second communications protocol stack, and

said second communications protocol stack corresponds to a bandwidth efficiency that is better than a bandwidth efficiency to which the first communications protocol stack corresponds.

8. A client side arrangement according to claim 7, wherein:

said client proxy comprises a first protocol stack arranged to correspond to the client application in its use of the first communications protocol stack,

said client proxy comprises a second protocol stack arranged to correspond to the server side arrangement in its use of the second communications protocol stack, and

said client proxy comprises an application layer entity located on top of said first and second protocol stacks and arranged to process digital data during protocol conversions.

9. A client side arrangement according to claim 8, wherein the application layer entity of the client proxy comprises:

a connection handler arranged to handle the processing of requests and responses conveyed through the client proxy,

coupled to said connection handler a cache memory arranged to store previously handled digital data, and

coupled to said connection handler at least one protocol handler arranged to perform conversions between the first and second communications protocol stacks.

10. A client side arrangement according to claim 9, wherein:

the application layer entity of the client proxy comprises, coupled to said connection handler, a number of protocol handlers each of which is arranged to perform conversions between a different first communications protocol and the second communications protocol stack.

11. A client side arrangement according to claim 9, wherein:

the application layer entity of the client proxy comprises multiplexing means for multiplexing several logically separate connections between the client proxy and the server side arrangement into a single connection therebetween.

12. A client side arrangement according to claim 11, wherein:

the client proxy is arranged to assign priorities to logically separate connections multiplexed by said multiplexing means, said priorities being based on at least one of the following;

observed user activity, explicitly stated preferences of a user, contents for the transferring of which the connections are used.

13. A client side arrangement according to claim 9, wherein:

said cache memory comprises a number of logically separate cache memories,

the separation of said cache memory into logically separate cache memories is based on at least one of the following;

user, user group, type of information stored,

the client proxy is arranged to conduct an expansive search through logically separate cache memories in order to look for certain requested digital data from other logically separate cache memories if that requested digital data was not found in a particular one of said logically separate cache memories, and

in conducting said expansive search, the client proxy is arranged to take into account existing access rights of a requesting party requesting said requested digital data.

14. A client side arrangement according to claim 9, wherein in using said cache memory said client proxy is arranged to apply at least one of:

an active caching algorithm designed for proactively preparing for a future need of certain digital data by the client application,

a predictive caching algorithm designed for predicting certain network locations from which contents should be downloaded and forwarded to the client application at some future moment of time,

a difference caching algorithm designed for reloading from a network only those parts of previously stored contents where changes have occurred,

an optimizing caching algorithm designed for optimizing, with respect to a limiting factor such as communication cost or amount of radio traffic, the amount and/or form of contents that should be downloaded from a network, and

a processing algorithm designed to improve response time by processing digital data stored in said cache memory prior to receiving an explicit request for such digital data from a client application.

15. A client side arrangement according to claim 7, wherein the first communications protocol stack is a combination of HTTP over TCP/IP and the second communications protocol stack is WAP.

16. A client side arrangement according to claim 7, wherein the client application and said client proxy are arranged to operate within a single physical device.

17. A client side arrangement according to claim 7, wherein the client application and said client proxy are arranged to operate within at least two physically separate devices.

18. A client side arrangement according to claim 7, wherein:

in a situation where a communications connection according to said second communications protocol stack with an access gateway at said server side arrangement is temporarily impossible, said client proxy is arranged to convey transferred digital data between the client application and a server application at the server side arrangement according to the first communications protocol stack.

19. A client side arrangement according to claim 18, wherein during a term of conveying transferred digital data between the client application and said server application at the server side arrangement according to the first communications protocol stack , said client proxy is arranged to repeatedly attempt resuming a communications connection according to said second communications protocol stack with an access gateway at the server side arrangement.

20. A server side arrangement for transferring digital data over a limited speed communication s link in communication with a client side arrangement located at a different side of the limited speed communications link than the server side arrangement, the server side arrangement comprising:

a server application arranged to receive and transmit digital data using a first communications protocol stack, and

an access gateway arranged to perform protocol conversions between the first communications protocol stack and a second communications protocol stack;

wherein;

said access gateway is arranged to convey transferred digital data between the client side arrangement and the server application so that between said client side arrangement and said access gateway digital data are transferred according to the second communications protocol stack, and

said second communications protocol stack corresponds to a bandwidth efficiency that is better than a bandwidth efficiency to which the first communications protocol stack corresponds.

21. A server side arrangement according to claim 20, wherein:

said access gateway comprises a first protocol stack arranged to correspond to the server application in its use of the first communications protocol stack,

said access gateway comprises a second protocol stack arranged to correspond to the client side arrangement in its use of the second communications protocol stack, and

said access gateway comprises an application layer entity located on top of said first and second protocol stacks and arranged to process digital data during protocol conversions.

22. A server side arrangement according to claim 21, wherein the application layer entity of the access gateway comprises:

a connection handler arranged to handle the processing of requests and responses conveyed through the access gateway,

coupled to said connection handler at least one cache memory arranged to store previously handled digital data, and

coupled to said connection handler at least one protocol handler arranged to perform conversions between the first and second communications protocol stacks.

23. A server side arrangement according to claim 22, wherein:

the application layer entity of the access gateway comprises, coupled to said connection handler, a number of protocol handlers each of which is arranged to perform conversions between a different first communications protocol and the second communications protocol stack.

24. A server side arrangement according to claim 22, wherein:

the application layer entity of the access gateway comprises multiplexing means for multiplexing several logically separate connections between the access gateway and the client side arrangement into a single connection therebetween.

25. A server side arrangement according to claim 22, wherein:

the application layer entity of the access gateway comprises, coupled to said connection handler, a number of logically separate cache memories,

the separation into logically separate cache memories is based on at least one of the following;

user, user group, client, client group, type of information stored,

the access gateway is arranged to conduct an expansive search through logically separate cache memories in order to look for certain requested digital data from other logically separate cache memories if that requested digital data was not found in a particular one of said logically separate cache memories, and

in conducting said expansive search, the access gateway is arranged to take into account existing access rights of a requesting party requesting said requested digital data.

26. A server side arrangement according to claim 22, wherein in using said at least one cache memory said access gateway is arranged to apply at least one of:

an active caching algorithm designed for proactively preparing for a future need of certain digital data by the client side arrangement,

a predictive caching algorithm designed for predicting certain network locations from which contents should be downloaded and forwarded to the client side arrangement at some future moment of time,

a first optimizing caching algorithm designed for optimizing, with respect to a limiting factor such as communication cost or amount of radio traffic, the amount and/or form of contents that should be forwarded to the client side arrangement,

a second optimizing caching algorithm designed for optimizing, with respect to a limiting factor such as communication cost or amount of network traffic, the amount and/or form of contents that should be reloaded from a network, and

a processing algorithm designed to improve response time by processing digital data stored in said at least one cache memory prior to receiving an explicit request for such digital data from a client side arrangement.

27. A server side arrangement according to claim 22, wherein the application layer entity of the access gateway comprises a coupling between said connection handler and an application layer protocol entity of the second communications protocol stack.

28. A server side arrangement according to claim 22, wherein the server application and said access gateway are arranged to operate within a single physical device.

29. A server side arrangement according to claim 22, wherein the server application and said access gateway are arranged to operate within at least two physically separate devices.

30. A method for transferring digital data over a limited speed communications link where a client side subarrangement and a server side subarrangement are located at different sides of the limited speed communications link, and within the client side subarrangement a client application is arranged to receive and transmit digital data using a first communications protocol stack and within the server side subarrangement a server application is arranged to receive and transmit digital data using the first communications protocol stack, the method comprising the steps of:

conveying transferred digital data between the client application and the server application through a client proxy within the client side subarrangement and an access gateway within the server side subarrangement,

performing in said client proxy protocol conversions between the first communications protocol stack and a second communications protocol stack that corresponds to a bandwidth efficiency that is better than a bandwidth efficiency to which the first communications protocol stack corresponds, and

performing in said access gateway protocol conversions between the first communications protocol stack and the second communications protocol stack;

so that between said client proxy and said access gateway digital data are transferred according to the second communications protocol stack.

31. A method according to claim 30, comprising the steps of:

a) routing a request received at the client proxy from the client application upwards through a first protocol stack into an application layer entity,

b) processing the request at the application layer entity of the client proxy,

c) if the processing of step b) reveals a need for communicating with the server side subarrangement, forwarding a processed request from the application layer entity of the client proxy downwards through a second protocol stack to the server side subarrangement, receiving a response from the server side subarrangement upwards through the second protocol stack and processing said response at the application layer entity of the client proxy; and

d) transmitting to the client application a response to the request received at step a), the transmission of said response going from the application layer entity of the client proxy downwards through the first protocol stack.

32. A method according to claim 31, wherein step b) comprises the substeps of:

b1) inquiring, whether the request received at step a) could be responded to by reading digital data from a cache memory at the application layer entity of the client proxy,

b2) if a positive response is received to the inquiry of step b1), proceeding to step d) without executing step c) because the processing of step b) did not reveal a need for communicating with the server side subarrangement; and

b3) if a negative response is received to the inquiry of step b1), calling a protocol handler at the application layer entity of the client proxy to process the request received at step a) into a form that accords with a protocol of the second communications protocol stack, and proceeding to execute step c).

33. A method according to claim 32, additionally comprising the steps of:

handling said cache memory as a number of logically separate cache memories on the basis of at least one of the following;

user, user group, type of information stored,

conducting at the client proxy an expansive search through logically separate cache memories in order to look for certain requested digital data from other logically separate cache memories if that requested digital data was not found in a particular one of said logically separate cache memories, and

in conducting said expansive search, the client proxy taking into account existing access rights of a requesting party requesting said requested digital data.

34. A method according to claim 32, additionally comprising at least one of the steps of:

actively updating digital data stored in said cache memory by applying an active caching algorithm designed for proactively preparing for a future need of certain digital data by the client application,

predictively updating digital data stored in said cache memory by applying a predictive caching algorithm designed for predicting certain network locations from which contents should be downloaded and forwarded to the client application at some future moment of time,

partially updating digital data stored in said cache memory by applying a difference caching algorithm designed for reloading from a network only those parts of previously stored contents where changes have occurred,

optimizing the process of downloading digital data from a network by applying an optimizing caching algorithm designed for optimizing, with respect to a limiting factor such as communication cost or amount of radio traffic, the amount and/or form of contents that should be downloaded from a network, and

processing digital data stored in said cache memory by applying a processing algorithm designed to improve response time by processing digital data stored in said cache memory prior to receiving an explicit request for such digital data from a client application.

35. A method according to claim 34, wherein in cases where at least one of the active-, predictive- or difference caching algorithms is applied, downloading from a network for the purposes of such applied algorithm is at least partly implemented through a background communication connection to the server side subarrangement, so that said background communication connection has a different priority in resource allocation than potentially occurring simultaneous service to requests from the client application.

36. A method according to claim 34, wherein in cases where at least one of the active-, predictive- or difference caching algorithms is applied, downloading from a network for the purposes of such applied algorithm is at least partly implemented through cost-optimized communication connections to the server side subarrangement, so that communication connections for the purposes of active caching are made during terms when communication cost is lower than a certain normal cost.

37. A method according to claim 34, wherein in cases where at least one of the active-, predictive- or difference caching algorithms is applied, downloading from a network for the purposes of such applied algorithm is at least partly implemented through traffic-optimized communication connections to the server side subarrangement, so that communication connections for the purposes of active caching are made during terms when other communications traffic with the server side subarrangement is lower than a certain normal value.

38. A method according to claim 32, additionally comprising the step of updating digital data stored in said cache memory by generating and processing an internal request, forwarding the processed internal request from the application layer entity of the client proxy downwards through a second protocol stack to the server side subarrangement, receiving a response from the server side subarrangement upwards through the second protocol stack, processing said response at the application layer entity of the client proxy and storing digital data extracted from said response to said cache memory.

39. A method according to claim 31, wherein step c) comprises the substep of selecting a particular access gateway among a number of available access gateways at a number of available server side subarrangements, the selection being based on at least one of the following:

preconfigured information identifying a default access gateway, a dynamically obtained response to a query presented to a user, a dynamically obtained response to a query presented to a source within a network.

40. A method according to claim 31, wherein step c) comprises the substeps of:

encrypting said request from the application layer entity of the client proxy to the server side subarrangement before transferring the request over a limited speed communications link,

decrypting said request from the application layer entity of the client proxy to the server side subarrangement after transferring the request over a limited speed communications link,

encrypting said response from the server side subarrangement to the application layer entity of the client proxy before transferring the response over a limited speed communications link, and

decrypting said response from the server side subarrangement to the application layer entity of the client proxy after transferring the response over a limited speed communications link.

41. A method according to claim 31, wherein step c) comprises at least one of the substeps of:

authenticating the client proxy for at least one device at the server side subarrangement, and

authenticating at least one device at the server side subarrangement for the client proxy.

42. A method according to claim 31, wherein step c) comprises the substep of checking, whether other essentially simultaneous transmissions occur between the application layer entity of the client proxy and the server side subarrangement, and if so, multiplexing the processed request that is forwarded from the application layer entity of the client proxy towards the server side subarrangement into a single connection with the other essentially simultaneous transmissions.

43. A method according to claim 31, wherein step c) comprises the substeps of:

c1) routing a request received at the access gateway from the client side subarrangement upwards through the second protocol stack into an application layer entity,

c2) processing the request at the application layer entity of the access gateway,

c3) if the processing of step c2) reveals a need for communicating with a content provider, forwarding a processed request from the application layer entity of the access gateway downwards through the first protocol stack to a content provider, receiving a response from the content provider upwards through the first protocol stack and processing said response at the application layer entity of the access gateway; and

c4) transmitting to the client side subarrangement a response to the request received at step c1), the transmission of said response going from the application layer entity of the access gateway downwards through the second protocol stack.

44. A method according to claim 43, wherein step c2) comprises the substeps of:

c2/1) inquiring, whether the request received at step c1) could be responded to by reading digital data from a cache memory at the application layer entity of the access gateway,

c2/2) if a positive response is received to the inquiry of step c2/1), proceeding to step c4) without executing step c3) because the processing of step c2) did not reveal a need for communicating with a content provider; and

c2/3) if a negative response is received to the inquiry of step c2/1), calling a protocol handler at the application layer entity of the access gateway to process the request received at step c1) into a form that accords with a protocol of the first communications protocol stack, and proceeding to execute step c3).

45. A method according to claim 44, additionally comprising the steps of:

handling said cache memory as a number of logically separate cache memories on the basis of at least one of the following;

user, user group, client, client group, type of information stored,

conducting at the access gateway an expansive search through logically separate cache memories in order to look for certain requested digital data from other logically separate cache memories if that requested digital data was not found in a particular one of said logically separate cache memories, and

in conducting said expansive search, taking into account existing access rights of a requesting party requesting said requested digital data.

46. A method according to claim 44, additionally comprising at least one of the steps of:

actively updating digital data stored in said cache memory by applying an active caching algorithm designed for proactively preparing for a future need of certain digital data by the client side subarrangement,

predictively updating digital data stored in said cache memory by applying a predictive caching algorithm designed for predicting certain network locations from which contents should be downloaded and forwarded to the client side subarrangement at some future moment of time,

optimizing the process of forwarding digital data to the client side subarrangement by applying a first optimizing caching algorithm designed for optimizing, with respect to a limiting factor such as communication cost or amount of radio traffic, the amount and/or form of contents that should be forwarded to a client side subarrangement,

optimizing the process of downloading digital data from a network by applying a second optimizing caching algorithm designed for optimizing, with respect to a limiting factor such as communication cost or amount of network traffic, the amount and/or form of contents that should be downloaded from a network, and

processing digital data stored in said cache memory by applying a processing algorithm designed to improve response time by processing digital data stored in said at least one cache memory prior to receiving an explicit request for such digital data from a client side subarrangement.

47. A method according to claim 43, wherein the processing of a response at the application layer entity of the access gateway as a part of step c3) comprises adapting certain contents of the response for transmission over a limited speed communication link to a client side subarrangement, thus implementing portal functionality.

48. A method according to claim 47, wherein said adapting comprises at least one of the following:

adding information to the response, removing information from the response, replacing information in the response.

49. A method according to claim 47, wherein said adapting is made dynamically according to link conditions between the server side subarrangement and the client side subarrangement.

50. A method according to claim 47, wherein said adapting is made according to certain previously obtained knowledge about certain capabilities of the client side subarrangement.

51. A method according to claim 47, wherein said adapting is made according to certain previously obtained knowledge about certain explicitly expressed preferences of an identified user of the client side subarrangement.

52. A method according to claim 47, wherein said adapting is made according to certain previously obtained knowledge about certain implicitly revealed behaviour of an identified user of the client side subarrangement.