1. A communications device which transmits stream data to an external communications device via a communications medium through packet communications,
the communications device comprising:
an encoding rate altering section which alters an encoding rate of the stream data;
an encoding rate managing section which controls alteration of the encoding rate;
a channel conditions measurement section which measures channel conditions in the communications medium;
an error resilience adding section which adds error resilience to packets to be transmitted; and
an error resilience managing section which controls the error resilience added by the error resilience adding section, wherein
the encoding rate managing section including an encoding rate determining section which determines the encoding rate in accordance with information on valid period of the stream data,
the information on valid period of the stream data is information on a time limit within which the stream data transmitted from the communications device should be reproduced at the external communications device, and
the error resilience managing section calculates a packet error rate of packets transmitted in a predetermined time period in accordance with the channel conditions having been measured by the channel conditions measurement section, and performs controls so as to (i) alter the error resilience to a higher error resilience if the packet error rate is not less than a threshold value and to (ii) lower the error resilience regardless of the channel conditions having been measured by the channel conditions measurement section if a predetermined time period has elapsed without alteration of the error resilience.
2. The communications device according to claim 1, wherein:
the encoding rate determining section determines the encoding rate in accordance with information on delay time until the encoding rate altering section actually alters the encoding rate after the encoding rate determining section instructs the encoding rate altering section to alter the encoding rate.
3. The communications device according to claim 1, further comprising:
a transmission buffer which temporarily stores data to be transmitted; and
a channel conditions measurement section which measures channel conditions in the communications medium,
the encoding rate managing section further including:
a transmission capacity calculating section which calculates a transmission capacity of packets transmitted in a predetermined time period, in accordance with the channel conditions having been measured by the channel conditions measurement section,
wherein:
the encoding rate determining section determines the encoding rate in accordance with the calculated transmission capacity and an amount of data stored in the transmission buffer, as well as the information on valid period of the stream data.
4. The communications device according to claim 3, wherein:
the encoding rate managing section calculates the transmission capacity in accordance with an amount of successfully transmitted data which is measured by the channel conditions measurement section.
5. The communications device according to claim 3, wherein:
the encoding rate determining section predicts that a future transmission capacity will be lower than the current transmission capacity at any time, and determines the encoding rate in accordance with the predicted future transmission capacity.
6. The communications device according to claim 3, wherein:
the encoding rate managing section further include a transmission capacity memory section which stores the transmission capacity calculated by the transmission capacity calculating section, and
the encoding rate determining section determines the encoding rate in accordance with past transmission capacities stored in the transmission capacity memory section and the amount of data stored in the transmission buffer.
7. The communications device according to claim 1, wherein:
the error resilience managing section calculates a current transmission capacity in accordance with the packet error rate having been measured by the channel conditions measuring section, compares between the current transmission capacity and a maximum transmission capacity that is transmittable at the higher error resilience, and then performs control for strengthening of the error resilience if the current transmission capacity is below the maximum transmission capacity at the higher error resilience.
8. The communications device according to claim 1, further comprising:
a communications section which serves as a physical layer in performing data transmission via the communications medium,
wherein:
the error resilience managing section controls the error resilience by altering a physical layer communications speed set by the physical layer of the communications section.
9. The communications device according to claim 1, wherein:
the error resilience managing section controls the error resilience by instructing the error resilience adding section to alter an encoding scheme andor an encoding parameter of an error correcting code.
10. The communications device according to claim 1, wherein:
the encoding rate determining section sets the encoding rate to at least one of a maximum encoding rate and a minimum encoding rate.
11. The communications device according to claim 1, wherein:
the encoding rate altering section alters the encoding rate of the stream data to (a) an encoding rate determined by the encoding rate determining section or (b) an encoding rate that is nearest to the encoding rate (a) among a plurality of encoding rates for encoding of the same stream data.
12. A computer-readable medium having instructions stored thereon, said instructions are read and executed by a processor for causing the processor to function as each section of the communications device according to claim 1.
13. A communications system comprising:
the communications device according to claim 1; and
a receiving device which is capable of communications with said communications device via a communications medium, and receives stream data from said communications device.
14. A communications device which transmits stream data to an external communications device via a communications medium through packet communications,
the communications device comprising:
an encoding rate altering section which alters an encoding rate of the stream data;
an encoding rate managing section which controls alteration of the encoding rate,
the encoding rate managing section including an encoding rate determining section which determines the encoding rate in accordance with information on delay time until the encoding rate altering section actually alters the encoding rate after the encoding rate determining section instructs the encoding rate altering section to alter the encoding rate, the delay time until the encoding rate is actually altered is a time based on a period during which the encoding rate altering section cannot alter the encoding rate;
a channel conditions measurement section which measures channel conditions in the communications medium;
an error resilience adding section which adds error resilience to packets to be transmitted; and
an error resilience managing section which controls the error resilience added by the error resilience adding section,
wherein:
the error resilience managing section calculates a packet error rate of packets transmitted in a predetermined time period in accordance with the channel conditions having been measured by the channel conditions measurement section, and performs controls so as to (i) alter the error resilience to a higher error resilience if the packet error rate is not less than a threshold value and to (ii) lower the error resilience regardless of the channel conditions having been measured by the channel conditions measurement section if a predetermined time period has elapsed without alteration of the error resilience.
15. The communications device according to claim 14, further comprising:
a transmission buffer which temporarily stores data to be transmitted; and
a channel conditions measurement section which measures channel conditions in a communications medium,
the encoding rate managing section further including:
a transmission capacity calculating section which calculates a transmission capacity of packets transmitted in a predetermined time period, in accordance with the channel conditions having been measured by the channel conditions measurement section,
wherein:
the encoding rate determining section determines the encoding rate in accordance with the calculated transmission capacity and an amount of data stored in the transmission buffer, as well as the information on delay time.
16. The communications device according to claim 15, wherein:
the encoding rate determining section predicts that a future transmission capacity will be lower than the current transmission capacity at any time, and determines the encoding rate in accordance with the predicted future transmission capacity.
17. The communications device according to claim 15, wherein:
the encoding rate managing section further include a transmission capacity memory section which stores the transmission capacity calculated by the transmission capacity calculating section, and
the encoding rate determining section determines the encoding rate in accordance with past transmission capacities stored in the transmission capacity memory section and the amount of data stored in the transmission buffer.
18. The communications device according to claim 15, wherein:
the encoding rate managing section calculates the transmission capacity in accordance with an amount of successfully transmitted data which is measured by the channel conditions measurement section.
19. The communications device according to claim 14, wherein:
the error resilience managing section calculates a current transmission capacity in accordance with the packet error rate having been measured by the channel conditions measuring section, compares between the current transmission capacity and a maximum transmission capacity that is transmittable at the higher error resilience, and then performs control for strengthening of the error resilience if the current transmission capacity is below the maximum transmission capacity at the higher error resilience.
20. The communications device according to claim 14, further comprising:
a communications section which serves as a physical layer in performing data transmission via the communications medium,
wherein:
the error resilience managing section controls the error resilience by altering a physical layer communications speed set by the physical layer of the communications section.
21. The communications device according to claim 14, wherein:
the error resilience managing section controls the error resilience by instructing the error resilience adding section to alter an encoding scheme andor an encoding parameter of an error correcting code.
22. The communications device according to claim 14, wherein:
the encoding rate determining section sets the encoding rate to at least one of a maximum encoding rate and a minimum encoding rate.
23. The communications device according to claim 14, wherein:
the encoding rate altering section alters the encoding rate of the stream data to (a) an encoding rate determined by the encoding rate determining section or (b) an encoding rate that is nearest to the encoding rate (a) among a plurality of encoding rates for encoding of the same stream data.
24. A communications device which performs packet communications to an external communications device via a communications medium,
the communications device comprising:
a channel conditions measurement section which measures, at a transmitting end of the communications device, channel conditions in the communications medium;
an error resilience adding section which adds error resilience to packets to be transmitted;
an error resilience managing section which controls the error resilience added by the error resilience adding section;
a communications section which serves as a physical layer in performing data transmission via the communications medium;
the channel conditions measurement section measures a physical layer communications speed and a packet error rate, the physical layer communications speed being set by the physical layer of the communications section; and
an encoding rate managing section andor the error resilience managing section calculates the transmission capacity in accordance with the physical layer communications speed and the packet error rate both of which are measured by the channel conditions measurement section,
wherein:
the error resilience managing section calculates the packet error rate of packets transmitted in a predetermined time period in accordance with the channel conditions having been measured by the channel conditions measurement section, and performs controls so as to (i) alter the error resilience to a higher error resilience if the packet error rate is not less than a threshold value and to (ii) lower the error resilience regardless of the channel conditions having been measured by the channel conditions measurement section if a predetermined time period has elapsed without alteration of the error resilience.
25. The communications device according to claim 24, further comprising:
a table memory section which stores a table representing a relationship between the physical layer communications speed and a maximum transmission capacity that is transmittable within a predetermined time period,
wherein:
the encoding rate managing section andor the error resilience managing section acquires a maximum transmission capacity, from the table, corresponding to the physical layer communications speed having been measured by the channel conditions measurement section, and then calculates the transmission capacity in accordance with the acquired maximum transmission capacity and the packet error rate having been measured by the channel conditions measurement section.
26. The communications device according to claim 25, wherein:
the channel conditions measurement section further measures a communications bandwidth allocated to said communications device for a predetermined time period, and
the encoding rate managing section andor the error resilience managing section calculates the transmission capacity in accordance with information on the physical layer communications speed and the communications bandwidth.
27. The communications device according to claim 25, wherein:
the channel conditions measurement section further measures a free bandwidth and an occupied bandwidth occupied by said communications device for a predetermined time period, and
the encoding rate managing section andor the error resilience managing section calculates the transmission capacity in accordance with the physical layer communications speed and information on the free bandwidth and the occupied bandwidth.
28. The communications device according to claim 24, wherein:
the error resilience managing section calculates a current transmission capacity in accordance with the packet error rate having been measured by the channel conditions measuring section, compares between the current transmission capacity and a maximum transmission capacity that is transmittable at the higher error resilience, and then performs control for strengthening of the error resilience if the current transmission capacity is below the maximum transmission capacity at the higher error resilience.
29. The communications device according to claim 24, further comprising:
a communications section which serves as a physical layer in performing data transmission via the communications medium,
wherein:
the error resilience managing section controls the error resilience by altering a physical layer communications speed set by the physical layer of the communications section.
30. The communications device according to claim 24, wherein:
the error resilience managing section controls the error resilience by instructing the error resilience adding section to alter an encoding scheme andor an encoding parameter of an error correcting code.
31. A communications device which transmits stream data to an external receiving device via a plurality of relay stations through packet communications,
the communications device comprising:
an encoding rate altering section which alters an encoding rate of the stream data; and
an encoding rate managing section which controls alteration of the encoding rate,
wherein:
the encoding rate managing section compares between a total amount of data transmitted from said communications device and a total amount of data received by the receiving device so as to predict amounts of data stored in the transmission buffer of said communications device and transmission buffers of the respective relay stations, and determines the encoding rate in accordance with the predicted amounts of stored data and the total amount of data received by the receiving device.
32. A communications method for transmitting stream data to an external communications device via a communications medium through packet communications,
the communications method comprising:
altering an encoding rate of the stream data;
controlling alteration of the encoding rate;
measuring channel conditions in the communications medium;
adding error resilience to packets to be transmitted;
controlling the error resilience added; and
calculating a packet error rate of packets transmitted in a predetermined time period in accordance with the measured channel conditions, and performing controls so as to (i) alter the error resilience to a higher error resilience if the packet error rate is not less than a threshold value and to (ii) lower the error resilience regardless of the measured channel conditions if a predetermined time period has elapsed without alteration of the error resilience,
wherein the encoding rate is determined in accordance with information on valid period of the stream data, and
the information on valid period of the stream data is information on a time limit within which the stream data transmitted from the communications device should be reproduced at the external communications device.
33. A communications method for transmitting stream data to an external communications device via a communications medium through packet communications,
the communications method comprising:
altering an encoding rate of the stream data; and
controlling alteration of the encoding rate,
wherein the encoding rate is determined in accordance with information on delay time until the encoding rate is actually altered after a receipt of encoding rate alteration instruction, the delay time until the encoding rate is actually altered is a time based on a period during which the encoding rate cannot be altered;
measuring channel conditions in the communications medium;
adding error resilience to packets to be transmitted;
controlling the added error resilience;
calculating a packet error rate of packets transmitted in a predetermined time period in accordance with the measured channel conditions; and
performing controls so as to (i) alter the error resilience to a higher error resilience if the packet error rate is not less than a threshold value and to (ii) lower the error resilience regardless of the measured channel conditions if a predetermined time period has elapsed without alteration of the error resilience.
34. A communications method for performing packet communications with respect to an external communications device via a communications medium, where a communications section serves as a physical layer in performing data transmission via the communications medium,
the communications method comprising:
measuring channel conditions in the communications medium at a transmitting end of a communications device;
adding error resilience to packets to be transmitted;
controlling the error resilience added; and
measuring a physical layer communications speed and a packet error rate, the physical layer communications speed being set by the physical layer of the communications section, and
calculating the transmission capacity in accordance with the physical layer communications speed and the packet error rate,
wherein the packet error rate of packets transmitted in a predetermined time period is calculated in accordance with the channel conditions having been measured, and controls are performed in such a manner that (i) the error resilience is altered to a higher error resilience if the packet error rate is not less than a threshold value and that (ii) the error resilience is lowered regardless of the channel conditions having been measured if a predetermined time period has elapsed without alteration of the error resilience.
35. A communications method for transmitting stream data from a communications device to an external receiving device via a plurality of relay stations through packet communications,
the communications method comprising:
altering an encoding rate of the stream data; and
controlling alteration of the encoding rate,
wherein comparison is performed between a total amount of data transmitted from the communications device and a total amount of data received by the receiving device so as to predict amounts of data stored in the transmission buffer of said communications device and transmission buffers of the respective relay stations, and the encoding rate is determined in accordance with the predicted amounts of stored data and the total amount of data received by the receiving device.
36. A computer-readable medium having instructions stored thereon, said instructions are read and executed by a processor for causing the processor to perform the communications method according to claim 35.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for providing at least one search result responsive to a search query comprising at least one search query term, the method comprising:
parsing a set of pages for a plurality of text and non-text indexable elements;
assigning a location identifier to one or more of the plurality of text and non-text indexable elements, the location identifier corresponding to a location of a given text and non-text indexable element in a given page from the set of pages and the location identifier is a pointer to the location of the given text and non-text indexable element;
storing the plurality of text and non-text indexable elements and the corresponding location identifier for the one or more of the plurality of text and non-text indexable elements in a computer readable medium as a plurality of records;
receiving the search query to request a stored record, the search query received from a user across a networked connection;
searching said plurality of records to determine text and non-text indexable elements that correspond to the search query;
transmitting at least one text element representation of said query result to the user across the networked connection; and
transmitting at least one non-text element representation of said query result to said user across the networked connection.
2. The method of claim 1, wherein the non-text elements comprises an image.
3. The method of claim 1, wherein the record comprises a Webpage.
4. The method of claim 1, wherein the non-text indexable element comprises a sound file.
5. A method for indexing records in an index of the world wide web, the method comprising:
receiving a record from the world wide web;
parsing the record for associated text and a non-text indexable elements;
creating representations of the parsed text and non-text indexable elements;
assigning a location identifier to one or more of the representations of the parsed text and non-text indexable elements, the location identifier corresponding to a location of a given text and non-text indexable element in the record and the location identifier is a pointer to the location of the given text and non-text indexable element; and
storing the representations and the corresponding location identifiers in association with the record as a one or more word location pairs.
6. The method of claim 5, wherein the non-text indexable element comprises an image.
7. The method of claim 5, wherein the record comprises a Web page.
8. A system for providing at least one search result responsive to a search query comprising at least one search query term, the system comprising:
a parse module for parsing the at least one record for text and non-text indexable elements and assigning a location identifier to one or more of the plurality of text and non-text indexable elements, the location identifier corresponding to a location of a given text and non-text indexable element in the at least one record;
an indexing module for indexing the text and non-text indexable elements and the corresponding location identifier for the one or more of the plurality of text and non-text indexable elements, the location identifier is a pointer to the location of the given text and non-text indexable element;
a query module for receiving the search query, the search query requesting at least one text and non-text indexable element in the world wide web, the search query received from a user across a networked connection;
a search module for locating corresponding text and non-text indexable element relating to the search query; and
a transmitter for transmitting a representation of the non-text indexable element and a text representation corresponding to the search query result to the user across the networked connection.
9. The system of claim 8, wherein the object comprises an image.
10. The system of claim 8, wherein the record comprises a Web page.
11. The system of claim 8, wherein the object comprises a hyperlink to a sound file.
12. A system for indexing records in an index of an information network, comprising:
a parser for parsing a record for text and non-text indexable elements;
a database for storing said text and non-text indexable elements;
an query module for searching the database for a link to said non-text indexable elements appearing in the record;
a subsystem for creating a representation of the text and non-text indexable elements and assigning a location identifier to the representation of the text and non-text indexable elements, the location identifier corresponding to a location of a given text and non-text indexable element in the record and the location identifier is a pointer to the location of the given text and non-text indexable element;
a subsystem for storing the representation and the corresponding location identifier in association with the record; and
a subsystem for making an entry for the record in the index including the representation and the corresponding location identifier.
13. The system of claim 12, wherein the object comprises an image.
14. The system of claim 12, wherein the record comprises a Web page.