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One of the issues that I heard wimax solves is the "make before break" problem. Supposedly 802.11 does not make a connection before breaking one (called a hard handoff). Is that true? I am starting to think it is not true. Is it impossible for 802.11 to connect to another access point while still moving data from the current AP?

The reason I ask is I was reading a document by Bernard Aboba, in which he says that 802.11 using 802.1x can authenticate to multiple access points at once, allowing "make before break". He doesn't go into how this works, well maybe he does but I didn't catch it!

info on soft and hard handoffs in wimax:
http://www.wimaxforum.org/technology/downloads/Applications_for_802.16-2004_and_802.16e_WiMAX_networks_final.pdf

Handoffs and roaming

Support for handoffs is another crucial addition in the 802.16e amendment for mobile
access. The ability to maintain a connection while moving across cell borders is a
prerequisite for mobility and will be included as a requirement in the 802.16e system
profile. While the 802.16-2004 standard offers optional handoff capabilities, support for
handoffs is not required by the 802.16-2004 system profile.
802.16e WiMAX will support different types of handoff, ranging from hard to soft and it
is up to the operator to choose among them. Hard handoffs use a break-before-make
approach – the user device is connected to only one base station at any given time –
which is less complex than soft-handoffs but has a high latency. Soft handoffs are
Figure 3. Uplink in OFDM and OFDMA
In OFDM, user devices are assigned time slots for transmission, but only one user device can transmit
during a single time slot. In OFDMA, sub-channelization enables several user devices to transmit at
the same time over the sub-channel(s) allocated to them.

comparable to those used in some cellular networks and allow the user device to retain
the connection to a base station until it is associated with a new one (make-before-break
approach), thus reducing latency. While applications like mobile Voice over Internet
Protocol (VoIP) or gaming greatly benefit from low-latency soft handoffs, hard handoffs
typically suffice for data services. QoS and Service Level Agreements (SLAs) are
maintained during handoffs.
Roaming capabilities across service providers can be implemented in both 802.16-2004
and 802.16e WiMAX, but they are especially valuable for portable and mobile access.
The WiMAX Forum does not expect to include roaming requirements in the 802.16e
system profile, as roaming is a higher level capability that goes beyond the scope of the
certification program, which focuses on the PHY and MAC layers. The Service Providers
Working Group and the Network Working Group within the WiMAX Forum are working
towards identifying the functional requirements for roaming and establishing a roaming
platform."