I feel that this post is going to be slightly less of a pure textual extrapolation than I like to aim for and more of an explication of my own thoughts on the utility of the transmission paradigm versus Ang's (?) indeterminacy of meaning drawing on Ang's observations.
One thing that continually bothers me about postmodernism is how it so frequently seems to validate a sense of uselessness. If the sender no longer has control over his/her/its message and meaning is created in myriad unpredictable interactions, how can we possibly gain any benefit from the study of this utterly chaotic system? Ang, (if that is his/her/its name...) I think effectively argues against the use of a transmission model of communication, but leaves very little in its place. Based on the observations Ang makes, it seems to me that one possible way to comprehend this new era of postmodern communication is not with the client-server transmission model, but with peer-to-peer. Ang notes that it is now well accepted that, "audiences are conceived as active producers of meanings and produce a diversity of readings" (168)... to me, this suggests that a fundamental change in communication in this new networked society comes from just that--the network. Previously in history, communication tended to operate one way; Roman currency bearing news of the new Emperor gradually diffused out into the provinces, but the Roman senator never had any need to contemplate the goings on in the provinces, European culture spread to colonized areas, but the colonies only sent back raw material instead of ideology, and the national press distributed information about the common imagined community that was the country to the remotest regions of the territory but was rarely influenced by the ideologies coming out of these areas. This was client-server, this was the myriad distant nodes of the network dialing in to the same message and granting so much value to that one transmitting node that the information it distributed was gospel and it seemed reasonable to describe the type of communication going on by juxtaposing the sender and the receiver as two separate entities. I think that networking has been the change that Ang picks up on in his/her essay.
Admittedly, Ang does identify Curran's conception of the transmission model as "simplistic" and "one-dimentional" (170) but in doing so I believe he does away with a useful tool in analyzing the status quo. It has been my experience that communication in the transmission style works on a small scale--a powerful orator can sway and persuade an audience. The difficulty that Ang seems to have with this model is that when it is blown up to a grand national scale, there is static--too much information flying this way and that do seem to cloud the transmission and blur the information being sent. However, I do not think it is proper to do away with the transmission model because of this but rather to reconfigure it; if the transmission model has legitimacy on a small scale, then perhaps it would be practical to analyze the whole of national and international communication as a series of interconnected transmission networks. In this context, every message released by, say, a large media organization is filtered through various networks to millions of nodes that now in a networked era have the power to process that message, rebroadcast it along the same channels that it followed originally and new ones. The message can collide with other messages, recombine and change in different nodes, and re-intersect the path of its origin to fundamentally alter the message received at every node in a multitude of ways. This interpretation preserves the conception of the transmission model on a small scale, as one communication of one sender to one receiver is liable to have an influence in that direction, but it also accounts for Ang's observation that any sort of massive distribution of a single message is necessarily difficult because of the exponentially larger amount of static that accumulates from a reverberating message. This reading both allows the use of the transmission model that has presumably demonstrated its utility in critical analysis before now, as well as introducing the new element of unpredictable static that Ang wishes to recognize.
Ang takes issue with the transmission model in part because it assumes a level of control of the sender over the receiver when, as Mark Poster argues, "it is faced with the formidable task of unveiling structures of domination when no one is dominating, nothing is being dominated, and no ground exists for a principle of liberation from domination" (170) If no domination is visible, I would suggest that is because we do not look closely enough. As I mentioned, the transmission model does have legitimacy on a small scale, and so by viewing the modern interconnected world as a series of small one-way messages with double-links and loops and circuits, then I think we can get a better picture of what has remained constant and what has changed, and from there base the new theory that Ang searches for in "In the realm of uncertainty."