Apparatus and methods of multiplexing data to a communication channel

• US 6,490,298 B1
• Filed: 02/26/1999
• Issued: 12/03/2002
• Est. Priority Date: 02/26/1999
• Status: Expired due to Term

• Current Assignee: Harmonic Incorporated
• Original Assignee: Harmonic Incorporated
• Inventors: Helms, William L., Haskell, Paul E., Chin, Amanda L.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): SPAFFORD, TIMOTHY J
• Application Number:
  US09/258,508
• Time in Patent Office: 1,376 Days
• Field of Search: 370/232, 370/235, 370/395.61, 370/395.64, 370/395.65, 370/532, 370/537, 370/538, 370/395.4, 370/395.43
• US Class Current: 370/532
• CPC Class Codes: H04L 7/033 using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop

Abstract

Apparatus and methods for multiplexing data received from a plurality of sources to a communication channel. Each of the sources is assigned to one of at least two scheduling layers based in part upon one or more bit rate characteristics of the sources.

Claims

1. An apparatus for multiplexing data received from a plurality of sources to a communication channel, comprising

a partitioner configured to assign each of the sources to one of at least two scheduling layers, including a first layer and a second layer, based (1) upon a fixed assignment method that operates independently of changes in data transmission rates of the sources;

and (2) at least in part upon one or more bit rate characteristics of the sources.

2. The apparatus of claim 1, wherein the partitioner is configured to assign each of the sources based at least in part on data transmission rates of the sources.

3. The apparatus of claim 1, wherein the partitioner is configured to assign each of the sources based at least in part upon bit rate precision levels of the sources.

4. The apparatus of claim 1, wherein the number of sources assigned to the first layer is variable.

5. The apparatus of claim 1, wherein the first layer comprises an entry for each source assigned to the first layer and an entry representative of a source assigned to the second layer, and the second layer comprises an entry for each source assigned to the second layer.

6. The apparatus of claim 5, further comprising a first layer scheduler configured to schedule the sources represented by entries in the first layer for output to the communication channel.

7. The apparatus of claim 6, wherein the first layer scheduler is configured to schedule sources for output based upon a variable bit rate scheduling method.

8. The apparatus of claim 5, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

9. The apparatus of claim 5, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

10. The apparatus of claim 5, further comprising a second layer scheduler configured to schedule the sources represented by entries in the second layer for assignment to the representative entry of the first layer.

11. The apparatus of claim 10, wherein the second layer scheduler is configured to schedule sources for assignment to the representative entry of the first layer based upon a variable bit rate scheduling method.

12. The apparatus of claim 5, wherein the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a sequence of one or more lower layers, based at least in part on one or more bit rate characteristics of the sources.

13. The apparatus of claim 12, wherein

the second layer comprises, in addition to an entry for each source assigned to the second layer, an entry representative of a source assigned to a first of the one or more lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer and an entry representative of a source assigned to the next lower layer in the sequence of one or more lower layers.

14. The apparatus of claim 13, further comprising a lower layer scheduler for the first of the one or more lower layers that is configured to schedule the sources represented by entries in that first lower layer for assignment to the representative entry of the second layer.

15. The apparatus of claim 12, wherein

the first layer comprises, in addition to the entry for each source assigned to the first layer and the entry representative of a source assigned to the second layer, a representative entry for each of the lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer.

16. The apparatus of claim 15, further comprising a lower layer scheduler for each of the lower layers that is configured to schedule sources for assignment to the representative entries of the first layer.

17. The apparatus of claim 1, wherein

the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a third layer, based at least in part on one or more bit rate characteristics of the sources,

the first layer comprises an entry for each source assigned to the first layer,

the second layer comprises an entry for each source assigned to the second layer, and

the third layer comprises an entry representative of a source assigned to the first layer and an entry representative of a source assigned to the second layer.

18. The apparatus of claim 17, wherein the partitioner is configured to assign each of the sources based at least in part on the data transmission rates of the sources.

19. The apparatus of claim 17, wherein the partitioner is configured to assign each of the sources based at least in part on the bit rate precision levels of the sources.

20. The apparatus of claim 17, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

21. The apparatus of claim 17, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

22. The apparatus of claim 1, further comprising a bit rate controller configured to assign to each source a data transmission rate and a bit rate precision level.

23. The apparatus of claim 22, wherein the bit rate controller is configured to assign to each source the same bit rate precision level.

24. The apparatus of claim 22, wherein the bit rate controller is configured to assign different bit rate precision levels to the sources.

25. The apparatus of claim 24, wherein the bit rate controller is configured to assign relatively high bit rate precision levels to audio sources, intermediate bit rate precision levels to video sources, and relatively low bit rate precision levels to data sources.

26. An apparatus for multiplexing data received from a plurality of sources to a communication channel, comprising

a partitioner configured to assign each of the sources to one of at least two scheduling layers, including a first layer and a second layer, based at least in part upon one or more bit rate characteristics of the sources, and wherein the partitioner is configured to assign the sources to the scheduling layers based upon a dynamic assignment method that responds to changes in data transmission rates of the sources.

27. The apparatus of claim 26, wherein the partitioner is configured to assign each of the sources based at least in part on data transmission rates of the sources.

28. The apparatus of claim 26, wherein the partitioner is configured to assign each of the sources based at least in part upon bit rate precision levels of the sources.

29. The apparatus of claim 26, wherein the number of sources assigned to the first layer is variable.

30. The apparatus of claim 26, wherein the first layer comprises an entry for each source assigned to the first layer and an entry representative of a source assigned to the second layer, and the second layer comprises an entry for each source assigned to the second layer.

31. The apparatus of claim 30, further comprising a first layer scheduler configured to schedule the sources represented by entries in the first layer for output to the communication channel.

32. The apparatus of claim 31, wherein the first layer scheduler is configured to schedule sources for output based upon a variable bit rate scheduling method.

33. The apparatus of claim 30, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

34. The apparatus of claim 30, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

35. The apparatus of claim 30, further comprising a second layer scheduler configured to schedule the sources represented by entries in the second layer for assignment to the representative entry of the first layer.

36. The apparatus of claim 35, wherein the second layer scheduler is configured to schedule sources for assignment to the representative entry of the first layer based upon a variable bit rate scheduling method.

37. The apparatus of claim 36, wherein

the first layer comprises, in addition to the entry for each source assigned to the first layer and the entry representative of a source assigned to the second layer, a representative entry for each of the lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer.

38. The apparatus of claim 37, further comprising a lower layer scheduler for each of the lower layers that is configured to schedule sources for assignment to the representative entries of the first layer.

39. The apparatus of claim 30, wherein the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a sequence of one or more lower layers, based at least in part on one or more bit rate characteristics of the sources.

40. The apparatus of claim 39, wherein

the second layer comprises, in addition to an entry for each source assigned to the second layer, an entry representative of a source assigned to a first of the one or more lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer and an entry representative of a source assigned to the next lower layer in the sequence of one or more lower layers.

41. The apparatus of claim 40, further comprising a lower layer scheduler for the first of the one or more lower layers that is configured to schedule the sources represented by entries in that first lower layer for assignment to the representative entry of the second layer.

42. The apparatus of claim 26, wherein

the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a third layer, based at least in part on one or more bit rate characteristics of the sources,

the first layer comprises an entry for each source assigned to the first layer,

the second layer comprises an entry for each source assigned to the second layer, and

the third layer comprises an entry representative of a source assigned to the first layer and an entry representative of a source assigned to the second layer.

43. The apparatus of claim 42, wherein the partitioner is configured to assign each of the sources based at least in part on the data transmission rates of the sources.

44. The apparatus of claim 42, wherein the partitioner is configured to assign each of the sources based at least in part on the bit rate precision levels of the sources.

45. The apparatus of claim 42, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

46. The apparatus of claim 42, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

47. The apparatus of claim 26 further comprising a bit rate controller configured to assign to each source a data transmission rate and a bit rate precision level.

48. The apparatus of claim 47, wherein the bit rate controller is configured to assign to each source the same bit rate precision level.

49. The apparatus of claim 47, wherein the bit rate controller is configured to assign different bit rate precision levels to the sources.

50. The apparatus of claim 49, wherein the bit rate controller is configured to assign relatively high bit rate precision levels to audio sources, intermediate bit rate precision levels to video sources, and relatively low bit rate precision levels to data sources.

51. An apparatus for multiplexing data received from a plurality of sources to a communication channel, comprising

a partitioner configured to assign each of the sources to one of at least two scheduling layers, including a first layer and a second layer, wherein the number of sources assigned to the first layer is fixed.

52. The apparatus of claim 51, wherein the partitioner is configured to assign each of the sources based at least in part on data transmission rates of the sources.

53. The apparatus of claim 51, wherein the partitioner is configured to assign each of the sources based at least in part upon bit rate precision levels of the sources.

54. The apparatus of claim 51, wherein the first layer comprises an entry for each source assigned to the first layer and an entry representative of a source assigned to the second layer, and the second layer comprises an entry for each source assigned to the second layer.

55. The apparatus of claim 54, further comprising a first layer scheduler configured to schedule the sources represented by entries in the first layer for output to the communication channel.

56. The apparatus of claim 55, wherein the first layer scheduler is configured to schedule sources for output based upon a variable bit rate scheduling method.

57. The apparatus of claim 54, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

58. The apparatus of claim 54, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

59. The apparatus of claim 54, further comprising a second layer scheduler configured to schedule the sources represented by entries in the second layer for assignment to the representative entry of the first layer.

60. The apparatus of claim 59, wherein the second layer scheduler is configured to schedule sources for assignment to the representative entry of the first layer based upon a variable bit rate scheduling method.

61. The apparatus of claim 54, wherein the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a sequence of one or more lower layers, based at least in part on one or more bit rate characteristics of the sources.

62. The apparatus of claim 61, wherein

the second layer comprises, in addition to an entry for each source assigned to the second layer, an entry representative of a source assigned to a first of the one or more lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer and an entry representative of a source assigned to the next lower layer in the sequence of one or more lower layers.

63. The apparatus of claim 62, further comprising a lower layer scheduler for the first of the one or more lower layers that is configured to schedule the sources represented by entries in that first lower layer for assignment to the representative entry of the second layer.

64. The apparatus of claim 61, wherein

the first layer comprises, in addition to the entry for each source assigned to the first layer and the entry representative of a source assigned to the second layer, a representative entry for each of the lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer.

65. The apparatus of claim 64, further comprising a lower layer scheduler for each of the lower layers that is configured to schedule sources for assignment to the representative entries of the first layer.

66. The apparatus of claim 51, wherein

the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a third layer, based at least in part on one or more bit rate characteristics of the sources,

the first layer comprises an entry for each source assigned to the first layer,

the second layer comprises an entry for each source assigned to the second layer, and

the third layer comprises an entry representative of a source assigned to the first layer and an entry representative of a source assigned to the second layer.

67. The apparatus of claim 66, wherein the partitioner is configured to assign each of the sources based at least in part on the data transmission rates of the sources.

68. The apparatus of claim 66, wherein the partitioner is configured to assign each of the sources based at least in part on the bit rate precision levels of the sources.

69. The apparatus of claim 66, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

70. The apparatus of claim 66, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

71. The apparatus of claim 51, further comprising a bit rate controller configured to assign to each source a data transmission rate and a bit rate precision level.

72. The apparatus of claim 71, wherein the bit rate controller is configured to assign to each source the same bit rate precision level.

73. The apparatus of claim 71, wherein the bit rate controller is configured to assign different bit rate precision levels to the sources.

74. The apparatus of claim 73, wherein the bit rate controller is configured to assign relatively high bit rate precision levels to audio sources, intermediate bit rate precision levels to video sources, and relatively low bit rate precision levels to data sources.

75. A method for multiplexing data received from a plurality of sources to a communication channel, comprising

assigning each of the sources to one of at least two scheduling layers, including a first layer and a second layer based (1) upon a fixed assignment method that operates independently of changes in data transmission rates of the sources;

and (2) at least in part upon one or more bit rate characteristics of the sources.

76. The method of claim 75, wherein each of the sources is assigned based at least in part upon data transmission rates of the sources.

77. The method of claim 75, wherein each of the sources is assigned based at least in part upon bit rate precision levels of the sources.

78. The method of claim 75, wherein the number of sources assigned to the first layer is variable.

79. The method of claim 75, wherein the first layer comprises an entry for each source assigned to the first layer and an entry representative of a source assigned to the second layer, and the second layer comprises an entry for each source assigned to the second layer.

80. The method of claim 79, further comprising scheduling the sources represented by entries in the first layer for output to the communication channel.

81. The method of claim 80, wherein the sources represented by entries in the first layer are scheduled for output based upon a variable bit rate scheduling method.

82. The method of claim 79, wherein sources with relatively high bit rates are assigned to the first layer.

83. The method of claim 79, wherein sources with relatively high bit rate precision levels are assigned to the first layer.

84. The method of claim 79, further comprising scheduling the sources represented by entries in the second layer for assignment to the representative entry of the first layer.

85. The method of claim 84, wherein the sources represented by entries in the second layer are scheduled sources for assignment to the representative entry of the first layer based upon a variable bit rate scheduling method.

86. The method of claim 79, wherein each of the sources is assigned to one of three or more scheduling layers, including the first layer, the second layer and a sequence of one or more lower layers, based at least in part upon one or more bit rate characteristics of the sources.

87. The method of claim 86, wherein

the second layer comprises, in addition to an entry for each source assigned to the second layer, an entry representative of a source assigned to a first of the one or more lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer and an entry representative of a source assigned to the next lower layer in the sequence of one or more lower layers.

88. The method of claim 87, further comprising scheduling the sources represented by entries in that first lower layer for assignment to the representative entry of the second layer.

89. The apparatus of claim 86, wherein

the first layer comprises, in addition to the entry for each source assigned to the first layer and the entry representative of a source assigned to the second layer, a representative entry for each of the lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer.

90. The method of claim 89, further comprising scheduling sources for assignment to the representative entries of the first layer.

91. The method of claim 75, wherein

each of the sources is assigned to one of three or more scheduling layers, including the first layer, the second layer and a third layer, based at least in part upon one or more bit rate characteristics of the sources,

the first layer comprises an entry for each source assigned to the first layer,

the second layer comprises an entry for each source assigned to the second layer, and

the third layer comprises an entry representative of a source assigned to the first layer and an entry representative of a source assigned to the second layer.

92. The method of claim 91, wherein each of the sources is assigned based at least in part upon the data transmission rates of the sources.

93. The method of claim 91, wherein each of the sources is assigned based at least in part upon the bit rate precision levels of the sources.

94. The method of claim 91, wherein sources with relatively high bit rates are assigned to the first layer.

95. The method of claim 91, wherein sources with relatively high bit rate precision levels are assigned to the first layer.

96. The method of claim 75, further comprising assigning to each source a data transmission rate and a bit rate precision level.

97. The method of claim 96, wherein the same bit rate precision level is assigned to each source.

98. The method of claim 96, wherein different bit rate precision levels are assigned to the sources.

99. The method of claim 98, wherein relatively high bit rate precision levels are assigned to audio sources, intermediate bit rate precision levels are assigned to video sources, and relatively low bit rate precision levels are assigned to data sources.

100. A method for multiplexing data received from a plurality of sources to a communication channel, comprising

assigning each of the sources to one of at least two scheduling layers, including a first layer and a second layer, based at least in part upon one or more bit rate characteristics of the sources, and wherein the sources are assigned to the scheduling layers based upon a dynamic assignment method that responds to changes in data transmission rates of the sources.

101. The method of claim 100, wherein the partitioner is configured to assign each of the sources based at least in part on data transmission rates of the sources.

102. The method of claim 100, wherein the partitioner is configured to assign each of the sources based at least in part upon bit rate precision levels of the sources.

103. The method of claim 100, wherein the number of sources assigned to the first layer is variable.

104. The method of claim 100, wherein the first layer comprises an entry for each source assigned to the first layer and an entry representative of a source assigned to the second layer, and the second layer comprises an entry for each source assigned to the second layer.

105. The method of claim 104, further comprising a first layer scheduler configured to schedule the sources represented by entries in the first layer for output to the communication channel.

106. The method of claim 105, wherein the first layer scheduler is configured to schedule sources for output based upon a variable bit rate scheduling method.

107. The method of claim 104, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

108. The method of claim 104, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

109. The method of claim 104, further comprising a second layer scheduler configured to schedule the sources represented by entries in the second layer for assignment to the representative entry of the first layer.

110. The method of claim 109, wherein the second layer scheduler is configured to schedule sources for assignment to the representative entry of the first layer based upon a variable bit rate scheduling method.

111. The method of claim 110, wherein

the first layer comprises, in addition to the entry for each source assigned to the first layer and the entry representative of a source assigned to the second layer, a representative entry for each of the lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer.

112. The method of claim 111, further comprising a lower layer scheduler for each of the lower layers that is configured to schedule sources for assignment to the representative entries of the first layer.

113. The method of claim 104, wherein the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a sequence of one or more lower layers, based at least in part on one or more bit rate characteristics of the sources.

114. The method of claim 113, wherein

the second layer comprises, in addition to an entry for each source assigned to the second layer, an entry representative of a source assigned to a first of the one or more lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer and an entry representative of a source assigned to the next lower layer in the sequence of one or more lower layers.

115. The method of claim 114, further comprising a lower layer scheduler for the first of the one or more lower layers that is configured to schedule the sources represented by entries in that first lower layer for assignment to the representative entry of the second layer.

116. The method of claim 100, wherein

the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a third layer, based at least in part on one or more bit rate characteristics of the sources,

the first layer comprises an entry for each source assigned to the first layer,

the second layer comprises an entry for each source assigned to the second layer, and

the third layer comprises an entry representative of a source assigned to the first layer and an entry representative of a source assigned to the second layer.

117. The method of claim 116, wherein the partitioner is configured to assign each of the sources based at least in part on the data transmission rates of the sources.

118. The method of claim 116, wherein the partitioner is configured to assign each of the sources based at least in part on the bit rate precision levels of the sources.

119. The method of claim 116, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

120. The method of claim 116, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

121. The method of claim 100, further comprising a bit rate controller configured to assign to each source a data transmission rate and a bit rate precision level.

122. The method of claim 121, where in the bit rate controller is configured to assign to each source the same bit rate precision level.

123. The method of claim 121, wherein the bit rate controller is configured to assign different bit rate precision levels to the sources.

124. The method of claim 123, wherein the bit rate controller is configured to assign relatively high bit rate precision levels to audio sources, intermediate bit rate precision levels to video sources, and relatively low bit rate precision levels to data sources.

125. A method for multiplexing data received from a plurality of sources to a communication channel, comprising

assigning each of the sources to one of at least two scheduling layers, including a first layer and a second layer, wherein the number of sources assigned to the first layer is fixed.

126. The method of claim 125, wherein the partitioner is configured to assign each of the sources based at least in part on data transmission rates of the sources.

127. The method of claim 125, wherein the partitioner is configured to assign each of the sources based at least in part upon bit rate precision levels of the sources.

128. The method of claim 125, wherein the first layer comprises an entry for each source assigned to the first layer and an entry representative of a source assigned to the second layer, and the second layer comprises an entry for each source assigned to the second layer.

129. The method of claim 128, further comprising a first layer scheduler configured to schedule the sources represented by entries in the first layer for output to the communication channel.

130. The method of claim 129, wherein the first layer scheduler is configured to schedule sources for output based upon a variable bit rate scheduling method.

131. The method of claim 128, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

132. The method of claim 128, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

133. The method of claim 128, further comprising a second layer scheduler configured to schedule the sources represented by entries in the second layer for assignment to the representative entry of the first layer.

134. The method of claim 133, wherein the second layer scheduler is configured to schedule sources for assignment to the representative entry of the first layer based upon a variable bit rate scheduling method.

135. The method of claim 128, wherein the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a sequence of one or more lower layers, based at least in part on one or more bit rate characteristics of the sources.

136. The method of claim 135, wherein

the second layer comprises, in addition to an entry for each source assigned to the second layer, an entry representative of a source assigned to a first of the one or more lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer and an entry representative of a source assigned to the next lower layer in the sequence of one or more lower layers.

137. The method of claim 136, further comprising a lower layer scheduler for the first of the one or more lower layers that is configured to schedule the sources represented by entries in that first lower layer for assignment to the representative entry of the second layer.

138. The method of claim 135, wherein

the first layer comprises, in addition to the entry for each source assigned to the first layer and the entry representative of a source assigned to the second layer, a representative entry for each of the lower layers, and

each lower layer comprises an entry for each source assigned to that lower layer.

139. The method of claim 138, further comprising a lower layer scheduler for each of the lower layers that is configured to schedule sources for assignment to the representative entries of the first layer.

140. The method of claim 125, wherein

the partitioner is configured to assign each of the sources to one of three or more scheduling layers, including the first layer, the second layer and a third layer, based at least in part on one or more bit rate characteristics of the sources,

the first layer comprises an entry for each source assigned to the first layer,

the second layer comprises an entry for each source assigned to the second layer, and

the third layer comprises an entry representative of a source assigned to the first layer and an entry representative of a source assigned to the second layer.

141. The method of claim 140, wherein the partitioner is configured to assign each of the sources based at least in part on the data transmission rates of the sources.

142. The method of claim 140, wherein the partitioner is configured to assign each of the sources based at least in part on the bit rate precision levels of the sources.

143. The method of claim 140, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rates.

144. The method of claim 140, wherein the partitioner is configured to assign to the first layer sources with relatively high bit rate precision levels.

145. The method of claim 125, further comprising a bit rate controller configured to assign to each source a data transmission rate and a bit rate precision level.

146. The method of claim 145, wherein the bit rate controller is configured to assign to each source the same bit rate precision level.

147. The method of claim 145, wherein the bit rate controller is configured to assign different bit rate precision levels to the sources.

148. The method of claim 147, wherein the bit rate controller is configured to assign relatively high bit rate precision levels to audio sources, intermediate bit rate precision levels to video sources, and relatively low bit rate precision levels to data sources.